This faint visual magnitude 13.0 galaxy in Pegasus was viewed by me at "my site" on the same occasion as NGC-255 (above): a very windy night on 23 November 2006, when conditions were so cold and blustery that I only looked at nine objects with my 10" Orion SkyQuest Dob. Light pollution was evident at the horizons; yet as before, I seem to have recorded in my viewing notes a detail not suggested by the mere atlas page open before me. Several other observations that night were surprisingly good ones; perhaps the transparency was exceptional. I could hardly tell what the seeing was like, with my scope being buffeted about by the gusts! Later I looked at a recording weather station, located a thousand feet below my observing point: wind was hitting more than 30mph, and I had to use heavy paperweights just to keep my atlas, and notebook, secure on the table next to me. Otherwise, something might have blown off, dropping over the sheer precipice past the road next to my scope, flying hundreds of feet straight down!

William Herschel's 18-1/2 inch aperture "speculum" mirror telescope (using the brightly polished reflective surface of a mirror consisting of a whitish alloy of tin, copper, and arsenic) captured this object for the great observer's eye. If his painstaking calculations are accurate, he was theoretically capable of observing stars to the 17th magnitude, until the moist English climate tarnished his "speculum", but his usual result achieved a limitation of 14th to 15th magnitude, which may be reached photographically or with CCD imaging, easily, by today's 10-inch aperture telescopes in a dark sky. Surprisingly for a hand-polished metal mirror, he reported very few instances of light scatter or flaring, even around bright stars (the rarity of this effect actually helped him discover a new type of object: the planetary reflection nebula, creating a halo of light reflected from dust particles and blown-off stellar atmosphere from a central star.)

Herschel spotted the object now called NGC-7042 in 1784. Its faint surface- brightness rating of 14.2 magnitude per square arcminute, and its moderately small angular diameter of 2.1 by 1.8 arcminutes, combined to make it a dim, obscure object, much fainter than the typical galaxies of Messier's catalogue. It is not likely to be viewed by amateur astronomers who cannot get to at least moderately dark semi-rural skies (which is just about the correct description of "my site".)

In his detailed search to correct and enhance the positions and ratings of objects in the NGC, Steve Gottlieb has viewed and reported about the galaxy, using a 17.5" Dobsonian. He comments that it is "fairly faint, moderately large, round, [with] bright core. Forms a pair with N7043 5.4' NE. A mag 12 star lies 2.3' NE between the galaxies" (this description is found on the NGC/IC Project page for the galaxy, and may also be accessed here, if you search for this exact string, less the quote marks: "NGC 7042".)

The POSS1 blue plate, used above for the picture, has been cropped to a field width of about 8 arcminutes in order to maximize the details of the galaxy. Just outside the picture, off to the upper left -- slightly more than 5 arcminutes to the NE of NGC-7042 -- is another galaxy, NGC-7043. It is much fainter (c.14th magnitude depending on the reference source, some of which claim as faint as 14.6, which would mean that 7042 is more than twice as bright), and only slightly more than half the diameter of 7042. It is interesting to learn that not Herschel but Albert Marth discovered it, 79 years later. Marth's telescope was the "Leviathan of Parsonstown", the 72 inch aperture reflecting telescope of Lord Rosse. No wonder he saw this object! It must have been quite distinct, if the Leviathan's mirror was not tarnished.

I was struck by the fact that William Herschel missed this galaxy. It would seem likely that he should  have seen it. I did not know of NGC-7043's dimness nor its close proximity on the night that I viewed 7042: for I was using only my Sky Atlas 2000.0 as a reference, which does not plot the fainter 7043! And, I did not have my laptop, which contains the star chart program that would have shown both of them, giving the appropriate data. So, either I too overlooked it; or it was simply too faint for the combination of my 10" scope, and the condition of the sky background glow, on the time of this observation. You can be sure I'll check this later, when possible, using my C-11.

My notebook records for NGC-7042 that it was a "gx, v faint, small patch with 6 mm Expanse [200x, 19' FOV, 1.3mm exit pupil]. Is there a halo? Is it offcenter E from the nucleus?" Apparently I did see the details of the faint outer arm in that direction. Since I had read absolutely nothing about it, aside from its magnitude and diameter, this observation was unbiased. This is one good reason not to go into an observing session with an exhaustive, detailed plan -- if you would like to see how well you can record unexpected details, or to pick up faint objects. Now, I'd be really pleased with myself if I had noticed 7043. Was it just below the visual threshold, or did I need at least the reassurance that something that faint was really there? Now, the spell is broken, and I can't accidentally 'discover' it myself...

Here's an obscurity! I could only locate two descriptions of amateur sightings (plus one small mistake) on public Internet websites, though there is always a chance it has been mentioned on a subscription forum somewhere. And, finding a picture is even more difficult. I could locate only one amateur image via Google; the cached thumbnail looked terrible, and the originating website would not come up. Why hasn't this object been investigated with more interest?

The discoverer was Dr. Max Wolf of Heidelberg Observatory, who photographed it in 1891, publishing a notification in the Astronomisches Nachrichten (AN 3027), which I have attempted to translate (freely) from the original German:

Of many other nebulae, whose reports are given here, the largest nebula was described in the previous year by Mr. Barnard around the stars G. C. 1420 Monocerotis, who was able to see that it extended over a much larger area than the circumferential disk of the star cluster. In that area, there is also a nebula not earlier photographed, at about the position of 6h 25m [right ascension] + 7d 30m [declination] and extending itself directly northwest of the 5th magnitude star 13 Monocerotis.

Presumably the coordinates are epoch 1875. "G. C. 1420" refers to NGC 2239, the open cluster at the heart of the Rosette Nebula; in 1883 Edward Barnard had traced the outer extent of the nebulosity, not seen before. I might add, parenthetically, that this is only one of many references that Max Wolf made to the observations of Barnard -- as well as respectful references by Barnard to Wolf -- which completely disproves the claim in Gerritt Verschuur's book Interstellar Matters that the astronomers were not only wary of each other, and very competitive, but NEVER referred to each other: this simply not true at all!

Wolf's measurement of the nebula was included in the Index Catalogue of 1895, in which it was described as "Neby, np *5 mag" (translated: nebulosity, north preceding star of 5th magnitude.") The star is SAO 114034 (4.47 magnitude, spectral type A0Ib: 06h 32m 54.23s RA, +07d 19m 58.7s dec.) The nebula measures about 15 by 10 arcminutes, and according to the listing of objects near the famous "Cone" nebula (NGC-2264) on the "Orion Arm page, is about 7 light years' diameter and 1,500 ly distant from earth. IC-448 is 3d 17m SSW from the Cone nebula, and 2d 20m north of the Rosette nebula.

The NGC/IC project page for IC-448 -- not directly linkable here -- identifies Lynds Bright Nebula 930 as being equivalent, but other resources specify LBN 931. The two Lynds nebulae overlap, 930 being much larger (30 by 20 arcminutes), to the east; 931 is to the west and encompasses the immediate region of 13-Mon: this is IC-448, which is shown in the heavily processed picture, above, from the POSS-UK survey blue plate, as being all the "fuzzy stuff" you can see around the star, in two 'clumps'. You may confirm these details with the Deep Sky Browser pages: for IC-448 (LBN 931) and for LBN 930.

My observation was done at "the site" on Saturday 1 October 2006, using my 10" aperture Orion SkyQuest Dob. I have prepared eyepiece performance charts for all my oculars and telescopes, using my own Eyepiece program (available free here), incorporating all the filter recommendations by Jack Marling for specific exit pupils. Therefore I have a good place to start my experimentation, as I can quickly find an appropriate field of view for my instrument, and know which filters will work in their most effective range for contrast enhancement. I examined all around 13-Mon, looking for the nebulosity, in both wide and narrow fields. Finally I settled on using my Orion "Highlight" 17 mm Plössl because in my previous tests I knew that it had higher light throughput transmission than any of my other oculars in that general focal length range: the best choice for extremely faint nebulae, and yielding slightly dimmer faint objects than my Orion "Expanse" 15 mm ocular. In my logbook I indicated that I thought that the Orion SkyGlow filter brought out the nebulosity, and drew what I thought was the brightest patch. My eyepiece chart indicated that the 17 mm Highlight would give me 70x, with a FOV of about 42 arcminutes and an exit pupil of 3.6 mm: right in range for the LPR, OIII, and UHC or hydrogen line filters. The SkyGlow is an LPR type, which one would use for reflection nebulae, as their bluish light is contained within the bandpass; the other types would diminish it.

My drawing was of course made from the scope's inverted, reversed view. I think that if one corrects for that, the spot that I was attempting to illustrate is the nebulous patch just to the upper right of the bright central star in the large (25 arcmin. square) photographic image above: in the orientation of that picture, the pole is up and the nebulous streak is pointing northward: almost straight up. Other aspects of the nebula may be seen better with a darker sky than I had on this particular occasion, and perhaps with a larger scope aperture (though then one must take care to get 13-Mon out of the immediate field, perhaps with an occulting bar.)

Among the very few references to the object by amateur astronomers, I found a mention by Albert Highe, who looked at it using a 12.5" Dobsonian at dark sky site near Hollister, California called Dinosaur Point, and stated only, "Because its [sic] near a bright star, its quite difficult to see." Jane Houston Jones referred to IC-448, using a Lake Sonoma, California observing site and her 17.5-inch f/4.5 reflector. There were many interesting and quite convincing descriptions in her report of numerous objects that she studied, but unfortunatly she seems to designate IC448 as an "open cluster": writing "NGC2259, NGC2252, CR111, IC448, CR97, CR96, CR92, CR104, CR107, CR110 Do22, IC2169 were other open clusters in this part of the Winter Milky Way I observed and checked off." I looked at all the objects in the immediate region and could not find an OCL with the designation "448" (nor anything remotely similar, or with numerical transpositions), so my guess is that she simply cut-and-pasted from a list of regional objects, wishing to include only clusters but accidentally nabbing also IC448 (goodness knows that MY articles probably have their share of mistakes too, and probably much more serious ones: that is why, for one reason, that I don't post my observations to other websites, as I want to be able to FIX the errors as soon as they are discovered!) Anybody else want to see if the nebula is visible?

0.5/2/4 degree finder chart: upright, correct.

Click here for my blog article reporting a sighting of IC-448 with my 4.7" refractor on 1/28/08.

There is little information about this planetary nebula on the Internet. I've turned up reports of sightings by six people, four of them Finnish amateurs. There are no amateur photos or CCD images to be found, every single picture on the net that I could locate being derived from the Digital Sky Survey sources. The NGC/IC project has not yet completed work on webpages for every object in the Index catalogue, so I had to do a little detective work to locate the discoverer: Thomas Henry Espinall Compton Espin, as may be confirmed by this scan of the appropriate page of the Second Index Catalogue. Espin and Dr. Max Wolf were the first 19th century astronomers to study the Cocoon nebula: see my article about it with informative links to a page about Espin, here.

There has been some significant interest in this planetary by professional astronomers. In 1996, Walter A. Feibelman of the Laboratory for Astronomy and Solar Physics, NASA/Goddard Space Flight Center, published a paper citing the work of Edwin Hubble, who photographed the spectrum in 1920, isolating nine emission lines; based on an exposure of 400 minutes with the IUE camera, several other spectral images, and his remeasurement of historical records, Fiebelman found "about 60 UV emission lines that were not detected before". Summarizing some important points in his paper: many other emission lines of carbon, oxygen, and iron were recorded or at least suspected. Strong stellar O VI emission lines were found which, along with at least a dozen other planetaries, characterize the object as belonging to the “O VI sequence”. Aller & Czyzak (1970) referred to IC 2003 as a uniform disk "..with a bright 'blob,' placed off to one side...They identified about 70 emission lines in the optical spectrum and also mentioned optical observations by Aller & Walker (1970) that show stratification effects."

I mention these last significant details, because my visual observation, a reprocessing by me of one of the DSS images, and another amateur's visual observation also depicted the brightness variation, as mentioned by Fiebelmann (which I did not know about until researching the object, the day after my own study of it in my telescope's eyepiece.)

As I've said so often, I don't go into most observing sessions with a fixed plan. Sometimes, when I use my Dob, I employ only a Sky Atlas 2000.0 chart and no other reference source (save the Companion to the Sky Atlas, a paperback volume that lists the plotted objects by chart, with extremely limited information about them: often only the type, position, and visual magnitude.) So, I had no preconceptions about IC-2003 when I looked at it at "my site".

The afternoon of Monday 8 January 2007 was unexpected sunny, brilliantly clear, and balmy in the San Francisco bay area. I finished my "chores" and readied myself at the very last moment for three or four hours of observing before the rise of the Moon at 10:27 pm. Normally, I prefer not to observe in the early evening, as light pollution at my locale in the mountains south of San Jose is rather severe, at least until after 1 or 2 am. But weather had been horrible during this winter season, and any possible moment for deep sky observing was to be snatched! I managed to be able to set up at 7pm, having donned my heaviest cold weather garments: layers and layers of pants, shirts, sweaters, and jackets (not to mention several head coverings.) But no sooner had I started looking when I realized I'd have to begin removing those layers, because the temperature did not drop precipitously after twilight commenced; instead it ROSE. By 8pm, the thermometer registered an amazing 59°F (15°C)! There wasn't a breath of wind. Soon I realized that my conditions were just like a summer night on the mountaintop; as if to confirm this, the seeing in the early part of the evening was probably the steadiest I'd experienced in many winters, perhaps reaching about 9 out of 10! Stars as faint as 8th magnitude were perfect pearly points in my eyepiece, surrounded by lovely, faint, unbroken, steady first diffraction rings. Double stars were exquisitely separated. But I wanted to spend the next couple of hours trying for faint deep stuff, benefiting from the amazing transparency and stillness of the air before the Moon ruined one's chances.

IC-2003 was the third object I sought. It was situated perfectly, high overhead where the stars were steadiest (I could spot ones as faint as perhaps 5.5 to 5.8 magnitude by eye: much better than usual at this short elapsed time past twilight.)

I have scanned and printed below my observing logbook note to show not only why I have talked about my "chicken scratchings", but also to indicate that I was at least trying to record more information than usual, for the purpose of adding something original to these reports (since some of my previous observation records have been so cryptic.) I described how the object looked with my highest powered eyepiece, and even added a 2x Barlow to that magnification. Since I had only recently installed a new Crayford focuser in my Orion 10" SkyQuest Dob, I was still revelling in the superb new experience of, at last, being able to focus this telescope REALLY sharply (something the old focuser wouldn't do.) I frankly had not realized before how good the optics in this cheap telescope really are; it gives my C-11 a run for the money. With the smooth action of the focuser, lacking any astigmatism or jerkiness, I was at last able to use comfortably my 3.7mm Orion "Epic" ocular [323x, 10' FOV, 0.8mm exit pupil], and for the purpose of studying the incredibly small planetary disk, I added my 2x "Shorty" Barlow [646x. 5' FOV, 0.4mm exit pupil], for the highest satisfactory magnification I have ever used for an astronomical observation with this telescope.

The planetary nebula's disk measures 7x6 arcseconds; it is rated at 11.6 visual magnitude (7.35 magnitude per square arcminute surface brightness), with a 15.4 magnitude central star. How did it look to me?

As you can see from my "scratchings", I perceived that it was a "small disk of slightly uneven brightness, possibly brighter to the SE? Thought I saw glimpses of brightness in the center: illusion?" The longer I watched it -- and this was extremely difficult, as the high magnification speeded up the movement of the object through the field of view, necessitating quite a bit of struggling with the clumsy alt-az mount -- the more I became convinced that I was seeing something in the center, a brightening that was extremely sharp and point-like; but it was not steady. It "flashed" in and out. I suppose it is theoretically possible to see a 15.4 magnitude star in this scope, since I can really quite easily do this with my C-11 (but that scope has a motor drive, and larger aperture, making such an observation infinitely easier.) I am not really willing to claim that I saw the central star, because it just wasn't steady and repeatable. But, I noticed that there was uneven surface brightness, and tried to indicate this in a (very crude) sketch. Since I was anxious not to lose dark adaptation, the sketch is poorer than it could have been; and it is out of scale compared to the full field sketch without the Barlow. (And I was in something of a hurry, wanting to get to as many objects in the region before the Moon rose.)

Update: As is my wont, I observed this object a day later, at 9:50pm on 9 January: same place, same scope. The seeing was steady but the sky was slightly 'softer' than before. With 646x, the "flashing" of brightness was apparent again, but perhaps not quite as distinct. It is difficult to hold an object in the field at this power; but over a period of time I decided I could detect two discrete flashes in different parts of the nebular disk, not just one. The brighter flash was near the periphery, and probably agrees with the enhanced photo, below. The other flash was seen less often, and could possibly be near the center.

There are four reports of seeing this nebula on the website of the Finnish Deep Sky Archive. Observer Jere Kahanpää, in Jyväskylä, Finland, looked at it with a 205mm aperture Newtonian in 1992, finding it to be at 63x "Stellar, surrounded by a group of stars of same magnitude"; later at an unspecified date, he used a Meade LPR filter and determined that it was "Very small. Maybe somewhat concentrated, round, quite sharp edges. Within a nice small asterism." My friend Jaako Saloranta, in Rajakylä, Vantaa, Finland, used his 8" aperture Dob with 122x and O-III filter, stating that it was a "Very small, stellar planetary with even brightness smooth disk." Juha Ojanperä (Friitala, Ulvila, Finland) used a 255 mm Newtonian at 145x: "Stellar planetary nebula, no details were seen." A larger aperture scope seems to have yielded much more information: Iiro Sairanen (at Härskiänsaari, Ruokolahti, Finland) employed an 18" Newtonian, and like me was able to use really high power. At 618x: "Quite small but very bright planetary nebula in Perseus. Stellar at low powers but at 618x there are some details on view. A clearly brighter crescent-shaped area in SE quadrant, annular? A 13th mag star on the West-side. The planetary is stellar or overexposed disk in every photo I've seen so it would be nice to see other observations of this." These observers all provide very helpful drawings; but your browser has to have Java enabled to bring up the pages. Iiro's picture is quite informative, and captures with careful shading his impression of the brightness variation, while mine is too crude to really represent what I saw by eye.

In an Internet post dating back to 1999, the experienced PN observer Yann Pothier comments that in his 17.5" Coulter Dob, the nebula was "visible at 45x; just non-stellar at 125x; OIII filter provides a very good contrast gain; at 145x and OIII, homognenous and sharp, about 9" in diameter, shapeless; a mag13.5 is 12" to the SW." And, Armin Herrman, observing in Thailand in 2004, reports that in a 15 inch Obsession f/4.5 Dob, IC-2003 was "brighter than its neighbor IC 351 which has a catalogued brightness of 12,0magv and should therefore be half a magnitude brighter than IC 2003! At 342x the PN shows a 7" disk that is brighter in the center. No central star seen. I did not see any color either."

I downloaded all the various DSS images using the Palomar, UK, and Hubble GSC pictures, and found that it was indeed true that most showed an overexposed disk. Only one picture had any real trace of brightness variations: the GSC 1 image. I examined this in a close-in region of 1 arcminute, capturing just the planetary and the star that is 18 arcseconds to the SE, which is GSC 2365:201, 13.4 magnitude. I blew it up and looked at the pixels: yes, the brightness variation was clearly shown, though each pixel was so large that not much detail could be resolved. I did a bit of contrast stretching and smoothing; the result is not guaranteed to be scientifically valid, but it does tend to suggest the bright "blob" mentioned by Fiebelmann, and at least something of the arc shown by Iiro. My own view, if my drawing is representative, was not quite as distinct.

If you would like to try examining this nebula, Mikkel Steine's Deep Sky Browser page for IC-2003 will supply finder charts and more information.

I have the distinct conviction that I did see some trace of this large, incredibly faint object. But the story is a bit complicated...

Abell 7 has a gigantic angular diameter of 14 by 11 arcminutes. The rated surface brightness of this relatively close, old planetary nebula is 18.3 magnitude per square arcminute (with a photographic magnitude 13.2 rating.) Can it be true that I could see any trace of the object at "my site", and with merely a 10" aperture scope? I'll leave it to my patient readers to decide, from the evidence given below.

To illustrate the faintness of this object, compare the modified, "contrast- stretched" image that I produced, above, with the original download (reduced in size slightly but otherwise unprocessed) of a 30 arcminute square section of the POSS/UK blue plate to the right. There is almost no immediately visible trace of the nebula, but the latent data are present if one takes the trouble to iterate many steps of contrast enhancement (which turns the picture's bright parts to rather ugly, burned in patches: note particularly the 14.5 magnitude galaxy, MCG -03-13-058 / PGC 16611, which has become a solid narrow ellipse just slightly above and to the right, or the west, of the planetary's center.)

Abell 7 is plotted in the Sky Atlas 2000.0 with its PK designation. I judged from the clarity of the sky (despite some residual light pollution to the east, far away from the region of the nebula) to be reasonably good at "my site" on the night of 9 January: the seeing was steady, with about 1 arcsecond resolution. The weather for the past two and a half days had been exquisitely clear. So I tried for the nebula, at its transit, assuming from past experience that I could almost always find the objects plotted in this atlas (with the exception of some of the faintest and largest nebulous patches, which require a darker site and a special wide-field telescope.)

At first, when I centered my field of view on the very distinctive apparent pair of stars close to the nebula -- SAO 150106 (7.5 mag) and GSC 5600:757 (10.3 mag), about 2 minutes separated -- that I could see what I noted as "a vaguely nebulous patch [to the east], around a zig-zag group of faint stars ranging from 11 to 12th magnitude" I used my 15mm Expanse ocular [80x, 49' FOV, 3.2 mm exit pupil] with no filtering and saw this indistinct glow; it was slightly more apparent with my 21 mm Stratus [57x, 70' FOV, 4.4 mm exit pupil] and became even more distinct with my SkyGlow filter, with averted vision. But, what's this? There was also a large, "uneven patch of nebulosity" on the western side of those two stars: this, in fact, turned out to be at least part of Abell 7. I tried higher and lower magnification: with my 32 mm eyepiece (an Orion Sirius model which, frankly, I don't like very much because of its poor eye relief) the sky was generally too bright; with a 9 mm wide field Expanse, the nebulosity disappeared though the background was slighly uneven as I scanned around the field. Adding either an UltraBlock or an OIII filter made this nebulous region stand out better.

The atlas plotted only a single star with the planetary immediately adjacent. But, try as I might, I kept preferring to think that there was more glow on the OTHER side of those two stars, than where the Abell object was indicated.

Ignorance is, as they say, bliss. But, in this case, it was torment! Were the nebulosities illusions? If not, which patch was the planetary, and what, then, was the "other stuff"?

As soon as I got home from observing, in the wee hours of the morning, I fired up the Internet and started researching the matter. It became immediately apparent that Abell 7 was indeed about 10-1/2 arcminutes to the northwest of those two stars, and not the other nebulous patch I had seen as well, toward the east, which appeared even perhaps a bit brighter by eye (no filter employed.) In other words, I did see some nebulosity: two patches, symmetrically positioned both to the NE and NW of those two stars: the western side being Abell 7, which responded to the OIII filter, and the eastern side being some other faint glow, which responded somewhat to my SkyGlow filter.

On the English-language version of Uwe Glahn's website article on the Abell planetaries, he comments that with his 16" telescope at 51x with OIII filter, Abell 7 is visible "only with max. AP [? -- srw] and [OIII], large, round PN, faint but can hold PN with averted vision, some faint structure, fainter to its middle, dark wedge from the west, PGC 16611 easy to detect, 10' NW of the PN, elongated 1:2", quite a definite observation. I did not detect PGC 16611, but probably merely because it had not been plotted on the Sky Atlas 2000.0 and thus wasn't sought out carefully by me; it is the sort of galaxy that would show up in my larger C-11 telescope. The very experienced Steve Gottlieb contributed one of his typically excellent writeups, observing at the California dark sky site Lake Sonoma with his 18" Starmaster Dob:

...at 73x and OIII filter, this ancient planetary appears as an extremely large, ghostly glow, perhaps 6' in diameter. Although the surface brightness is very low, it was visible as an irregularly-shaped, hazy patch involved with 5 or 6 stars on the south side. The edge of the planetary is better defined on the southern periphery and appears to fade out on the N side, so I was probably viewing only a portion of the object. Once identified, though, it was not difficult with averted vision.

Coincidentally, there's a very faint galaxy, MCG -03-13-058, just outside the edge of the halo, 10' NW of center! This required some hunting, though, as it's also a difficult object. And of course, the OIII filter had to go.

When I first wrote up this article, after only one viewing of the region, I located and linked to a 2001 report by Stathis Kafalis, who was seeking Abell 7 using a site that was infinitely better than mine (Canadas Tenerife, 28° latitude, 2300 meters elevation): with a 10" f/4.5 Dob,

At 43x (32 mm WF) without filter approx. 15' west of this position [i. e.,"RA 05:03 dec -15:36", referenced earlier in his post, the "official" position center for Abell 7] a group of 5-7 Stars of 11-13 mag. With OII filter sometimes extremly faint diffuse glow around and near this group of ~8' diameter. Is it the nebula or just the stars scattering through the filter? Very unsecure.

Unfortunately I misconstrued Strathis' description at first, which Sue French pointed out; she also helped me straighten out a blunder I made in one part of the original article where I had transposed E/W directions. With that correction, Strathis does not seem to be describing my anomalous nebular spot. If one changes his "west" to "east", then he could be describing my nebulous patch. It is probably more likely that he was seeing a relatively bright outlying edge of Abell 7. There are some stars within the periphery of the nebula, and a few c.12th magnitude stars to the west; a Hickson cluster to the northwest; but as I saw it, a very distinct grouping of stars to the EAST: they are indeed in the range of 11-13 magnitude and very well resemble his description for stars he describes as being to the "west".

In order to determine if 'my' perplexing glow was really there, I plotted the central coordinates based on my drawing, using a star chart program, determining approximately where it was centered; then I downloaded an equivalent region from those coordinates from the POSS/UK2 red, blue, and infrared plates. After doing even more heavy processing, I was able to bring up the faint background glow ONLY on the blue plate (tending to indicate that it could be reflection nebulosity, or at least a shorter wavelength than the red and IR plates would register.) In these three versions, heavily reprocessed, you will see in each picture those two stars identified above (smeared together into one overexposed mess), plus the edge of Abell 7's disk in the lower right hand corner. I believe from the blue plate it can be determined that there is a nebulosity around GSC 5901:972 (10.2 magnitude, at RA:05h 04m 12.7s / Dec:-15d 30' 18" Epoch 2000) and running for several arcminutes to the east of it ; there is also a somewhat fainter patch around and extending to the east of the two stars close to Abell 7, described above.

So, there is nebulosity there, recorded by this one picture, and it was likely right at the threshold of my perception -- even without a filter! The image in this paragraph, to the right, is yet another attempt, using an alternative method with different software, to process the faint background glow in the POSS/UK2 blute plate with less overexposure on the highlights. As distinct as this glow may be, however, an amateur CCD imager with today's best equipment could certainly do better, showing more nebulosity with better detail and less noise, using an appropriate LRGB exposure: any takers?

My conclusion is, therefore, that Abell 7 was at least partially (and barely) detected by me -- perhaps one small area of a brighter- than- average spot, "bright" being an entirely relative term! -- though it took some careful study from my drawing to determine, from relative positions, that it was at first confused with the apparently brighter variation in background glow: surely very similar to one of William Herschel's famous "regions of milky nebulosity."

As is my wont, to confirm a very difficult observation and see if I had been mistaken or deluded, I went to "my site" again on the night of Thursday, 11 January 2007 (sadly, too late to be able to see the setting of Comet McNaught.) But by the time that Abell 7 was transiting, conditions were probably as good as they had been 48 hours earlier: Sirius barely twinkled; a sharp line of temperature demarcation down near the valley floor had caused an inversion that was keeping much of the skyglow from Morgan Hill from escaping upward; and some clouds had drifted north of my mountain top, cutting off much of the light from San Jose. Once again, I looked closely at the region of Abell 7, and drew a sketch that was similar to the ones I had made previously, with the glow of a bright part of Abell 7, as well as 'my' anomalous nebulous patch to the east of it. (Unfortunately, it is immediately apparent, when comparing it to a star chart plot, that some of the fainter star positions are grossly inaccurate, the result of my having to walk about 20 feet over from the scope to the table with my charts and notepad, and back, several times while making the drawing!)

On this second night of observation of Abell 7, I found that using either my OIII or UltraBlock filter plus the 25 mm Orion Ultrascopic eyepiece yielded best contrast [48x, 1.1d FOV, 5.3 mm exit pupil]; I also tried for the widest possible field, using a 2" barrel 42 mm eyepiece, a bit too low in power for a practical exit pupil that fit my eye, but nevertheless still showing the two nebulous patches quite distinctly, employing a 2" UltraBlock filter [28x, 2.4d FOV, 8.9 mm exit pupil]. Unfortunately I did not have a 2" ocular that would yield a smaller, practical exit pupil of 7mm or less; I had acquired the 42 mm Erfle-type eyepiece for my C-11, not for the "fast" Dob.

Sue French provided some cautionary skepticism in her analysis of the situation as I had reported it. She wanted me to make certain that "my" glow could show up in more than just one picture: so I downloaded a one-degree region, centered on Abell 7's coordinates, from all the available images in the Digital Sky Survey. I then cropped, processed, stretched, and converted each to a negative view to make the background as distinct as possible.

The results indicate that the POSS1 blue plate -- at left -- has only a very vague and poor image of Abell 7, with a quite uneven background illumination, scratches, and no trace of "my" alleged nebulosity. It's a wonder that George Abell was able to detect the planetary with the techniques available years ago.

But the two GSC pictures did have at least something registered above the noise level, as well as much better distinction of Abell 7: GSG2 had more contrast, and carried more information.

GSG2 (below, left) does seem to suggest the slightest trace of nebulosity. However, the POSS2/UK blue plate (below, right) does indeed have the best rendering of my alleged nebulosity, though not as much density in the image of Abell 7 (admittedly, all of these nuances are quite easily altered by further tinkering; my reprocessing is not alleged to be scientifically precise and repeatably valid.)

These images of Abell 7 nevertheless are quite convincing that the "mean surface brightness of 18.3 magnitude per square arcminute" is not representative of every spot of the nebula. The reason I could see it with a 10" scope is surely because some places are significantly brighter and denser than others.

I have created a finder chart for Abell 7 on which I have used a spray-tool to indicate my claim of an "apparent glow" in the region, if another observer would care to look for it. Be aware of course that the giant purple circle pattern representing Abell 7 in this chart is merely an indication of position that has been colorized by the star chart program for clarity, and is not a realistic depiction. Owners of larger scopes than my 10" should also look for the Hickson galaxy cluster number 32, as well as nearby MCG -03-13-058.

Finally: thanks are extended to Sue French for her various suggestions and caveats, assisting me in the analysis of the observation and images.

0.5/2 degree finder: upright, correct

UPDATE: I now have some confirming observations of Abell 7, and even the glow to the east that is described above. While struggling to see details of some other faint objects in Lepus on Monday 19 February 2007, I found Abell 7 using a newly acquired Orion Q-70 2" barrel 32 mm ocular, and UltraBlock filter. And four days earlier, on Friday evening, I saw both the planetary and the nearby easterly nebulosity with that ocular in my 10" scope, recording in my notebook seeomg a "glow nr triangle of faint * even w lots of bg light." Thus I have quite good confidence that my initial impressions are repeatable, and should be possible by other observers.

'Visible only with 14 - 20 inch scope' -- the claim made by some high latitude observers who work in skies at low altitudes. But, it's just not so! Though the object was difficult, and required more than an hour's time to find, study, and then go back and confirm, I've acquired the planetary with my 10" Dob at "my site". It was frustrating; wasn't very 'satisfying'; and was a time-consuming, fatiguing experience: but, it was definitely achieved.

Between cold fronts, the northern California/SF bay area weather in January 2007 was surprisingly good for deep sky observing. During several nights and two early mornings, approaching the new moon, I found myself amazed at the steadiness of the atmosphere at 3,400 feet altitude above sea level, near the Pacific ocean. Whatever success I have in finding such obscure and faint objects as this one is due almost entirely to my altitude, and to the stable laminar air masses with which the mountain ranges around the famed "silicon valley" are blessed: thus, at Mt. Hamilton's Lick Observatory in the late nineteenth century, Barnard and S. W. Burnham were able to make many pioneering observations that, at the time, perturbed other professional astronomers, whose institutions were located unfavorably. My site is about 800 feet lower than the peak of Mt. Hamilton, but is closer to the Pacific ocean and separated from San Jose direct lights by the edge of the mountaintop. On favorable nights, lower elevation fog and clouds render it a true "dark sky site"; but unfortunately that happens rarely in the dead of winter. On the late night of Wednesday, 17 January, the light dome from San Jose was strongly glowing, turning the northern sky into a bland gray-blue glow, wiping out naked eye stars fainter than about 4.5 to 5 magnitude. BUT...to the southwest, the sky was incredibly darker, and at the zenith -- due to the wonderful transparency of the air -- it was excellent, reaching 6th magnitude.

I had been attracted to the idea of searching for Minkowski 1-18 from reading about it on the Yahoo Planetary Nebula group, and from one or two web pages that deigned to mention this obscurity. It was discovered in 1946 by the famed astronomer and director of the original Palomar Sky Survey, Rudolf Minkowski (according to this page of the 2000 version of the Kohoutek catalogue.) Because the telescopes at Palomar were not yet in full operation, I was curious about how the Minkowski planetaries of 1946 were discovered, and found nothing explicit on the Net. I was just about to send an email to my friend Don Osterbrock of Lick Observatory, who had written a monograph on Minkowski, to ask him for the details: but I discovered to my great dismay that he had passed away from a heart attack (as reported by Dr. Bill Sheehan in a Sky & Telescope web article) only a week before the day that I am composing this entry in my Fuzzy pages. However, there is a hint that I found about the discoveries of other Minkowski planetaries, in the long and useful list of 450 planetaries compiled by Jay McNeil: "Mount Wilson Plates" is the attribution for many of them, and thus it might possibly be true also for Min 1-18, unless I find better information subsequently. Could these plates have been taken during the World War II blackouts, when the Los Angeles basin lights were not blazing normally? In Minkowski's three papers ("New Emission Nebulae") in the Publications of the Astronomical Society of the Pacific (1946-48, links available on this list of references) one learns that most of them were measured on plates taken with the 60 inch and 100 inch telescopes using either the Newtonian or Cassegrain focus, and others were found on plates taken by John Charles Duncan and Albert George Wilson using the 18" Schmidt telescope at Palomar (an instrument which began operation in 1936.) But the object catalogued as Minkowski 1-18 does not appear in the lists of new objects given in those papers, adjusting for the J1950 coordinates, so I am still a bit puzzled about the details of the initial determination.

Minkowski 1-18 is fortunately situated only about 23 arcminutes almost due north of the famous planetary nebula NGC-2438 (07d 41m 51.43s RA, -14 43 54.9 dec), which glows distinctly "inside" the northern periphery of the open star cluster M-46 -- though it is most likely a foreground object -- putting it in an interesting region of the sky, close to very well known objects. Fortunate... for low-latitude observers close to the equator, that is. For at higher latitudes, so much atmospheric extinction occurs that even the very bright 2438 becomes vague, washed out, and pale. Luckily my local observing latitude is at approximately 37d, with M46 rising well above the heavy dull air blanket near the horizon. At transit, M46 is high enough to take on sharp clarity, "its" planetary nebula standing out beautifully (in fact, in years past when I was much younger, it seemed to glow quite blue at low power; now, at my upper-middle age, it is merely a distinct light gray.)

My determination to seek out Min 1-18 stemmed from some skeptical remarks made by an observer in the British Isles, who found the nebula to be a supreme challenge, even with a 20" aperture scope. I could sense that he looked on other observer's descriptions as being questionable, especially when relating the alleged "claim" that it had been seen by someone with a 10" aperture instrument. Well, the British Isles -- even the dark sky sites inland -- are simply no match for the California Pacific coast mountain ranges. I tried to get Min 1-18 on a disastrous trip to a staggeringly dark sky site in late December 2006, but moisture ruined the occasion, wasting almost 600 miles of driving. I'd have to try again but at the relatively light polluted site I normally use near home. So, philosophically, I just girded my loins for the struggle.

Success in finding this nebula is really determined by proper preparation. Unlike many of my spontaneous observations, merely seeing an object listed in my atlas and 'going for it', this nebula is so faint and tenuous -- by most accounts -- that one should really be familiar with the star field. So I used my planetarium program to print out a chart that contained a near field with stars down to 15th magnitude so that I could get a good correlation of shapes and relationships between the chart, and the eyepiece view. But I made certain NOT to look at a photograph. I consulted only the numbers: the location; the visual magnitude (14.0); the size (33 by 28 arcseconds); the central star (19.1 magnitude: impossible to detect with a 10 inch scope by means of the human eye.) I did not want to prejudice myself completely, and to create any self-delusion and conviction that I 'saw something I hadn't seen'.

The early part of the evening was propitious, and I had intended to wait until about a quarter of twelve o'clock, when the nebula transited; but I noticed some fleeting clouds to the NE and began to worry. So, an hour before transit time I started working on the object. The blinding and spectacular star Sirius, the beacon for finding Puppis, was so steady that one had to stare intently with naked eye to see even the slightest twinkling: an amazing phenomenon for the normally turbulent winter. Soon I had a beautiful view of M46 and the large, obvious planetary that shines through it.

Moving my scope north and increasing the magnification, I quickly came onto the exact location and could match the brighter stars. At higher power, the distinct pattern of three faint pairs of stars, which 'surround' the nebula in a broad arc, became fixed in my mind so that within ten to twenty minutes, I could move the scope away and return it immediately to the recognized position.

My logbook indicates that at about 11 pm I wrote, "I got it!" And at 11:15 I made my first of two drawings, noting at first that "Filters n. g. at any power, even low. Had to use high power, no filter: best with 3.7 mm" [323x, 10.2 arcmin or 0.2 deg. FOV, 0.8 mm exit pupil], which was my Orion "Epic" ED ocular. I also found that it was visible with a 6.3 mm Orion Highlight Plössl [191x, 16 min FOV, 1.3 mm exit pupil], and even used that eyepiece with my 2x "Shorty" Barlow [382x, 8 min FOV, 0.65 mm exit pupil]: no wonder filters would not work, as none of them would be in the proper exit pupil range and would cause too much extinction of light. In fact, that I could use such high magnification reliably with my Orion SkyQuest Dob was only a recent phenomenon, thanks to the focuser upgrade I had performed a few weeks earlier, installing a new Orion Crayford-style focuser to replace the old wobbly yet stiff rack-and-pinion job: I frankly doubt that I could have seen the nebula with that focuser at all, because I could not have been able to adjust the scope properly at magnifications over 200x.

I did of course test my filters, recording that "perhaps I saw it, barely, once momentarily with 7.5 mm ocular + UltraBlock" [160x, 18 arcmin FOV, 1.6 mm exit pupil], using my Orion Lanthanum eyepiece that I appreciate for its exceptionally high transmission. I also noted that it could be "detected, erratically", with the 12.5 mm Lanthanum plus SkyGlow LPR filter [96x, 31 arcmin FOV, 2.6 mm exit pupil], but both were only done after I had studied the object's visibility for more than a half hour with NO filters, making sure it really was perceptible. One has to be careful about the magnification employed, as low power will confuse the eye. The faint stars right on the periphery of the nebula's shell are indeed quite visible, and in a wide field might tend to create the optical illusion of a faint glow. High magnification will make them distinct -- at least in my scope, most of the time -- and show that they are not situated right on top of the actual faint fuzz patch. I wrote after almost 45 minutes of painstaking experimentation and observing that "It comes in and out every 2 to 4 seconds but does not stay absolutely steadily visible. Vfaint, right at threshold of perception. Adjust eye position to find best averted direction; can't quite hold directly straight-on." Then, another ten minutes later, after even more testing, I wrote with more assurance, "ALMOST straight-on using 10 mm Plössl + SkyGlow LPR filter" [120x, 25 arcmin FOV, 2.1 mm exit pupil]: exactly in range for best efficiency of contrast enhancement for the filter, in my particular scope.

The fact that I began detecting the nebula without any filter at all, by finding the precisely best exit pupil and magnification, would eliminate any tendency to be fooled by "optical illusions caused by filters", a claim that I've read a few times among skeptics who discount the observations of OTHER people who seem to be much better at finding faint nebulae. And the fact that the OIII filter did not seem to work was no surprise to me: because it functions best at low powers, where the nebula was just too small to be detected by my eye. Surely though the OIII will function properly in a giant aperture scope.

One other detail was noted by me, though not with absolute certainty: "perhaps it's not really round." I had the distinct feeling, in the moments that it 'faded' up above the background noise level, that it might be either unevenly bright or rather oval or rectangular to the eye. This is somewhat suggested, in fact, by the POSS/UK blue plate, above, which shows at least that it is somewhat brighter on the northern edge.

The nebula was incredibly faint, perhaps the dimmest object I have yet seen with this 10" telescope at "my site" (the image at left is my attempt to simulate how it might look at best in an eyepiece view, created by me with a modification of the POSS1 blue plate image in a 5 arcminute field, with the contrast of the nebula and some of the faintest stars "toned down" considerably.) Though the visual magnitude of 14 is not especially low -- and it does show up well in the Palomar Schmidt and UK Digital Sky Survey blue plates -- and the surface brightness is a relatively effective 12.53 mag/per square arcminute of area, at my location at +37 d north latitude the object was surely subjected to some undesirable atmospheric extinction below optimal. Even lowering the latitude by the 4 degrees at Palomar Mountain in San Diego county (33.3d, where the Digital Sky Survey POSS Schmidt plate of Min 1-18 was taken, and registered well) causes the planetary to gain significant clarity. Better still is the locale of the UK Anglo-Australian telescope, used for the DSS survey blue plate picture that I cropped in a 10 arcminute field at the top of this discussion. One does wonder, though, how well it could ever be seen at the few deep sky locales used by amateur astronomers in England (higher than 51 d.): no wonder amateurs there find the object an almost insurmountable challenge. But they should NOT discount the gains made by observers at mountain tops closer to the equator!

Indeed, I found one good viewing report on the public Net, in a webpage article by Jenny Kay, FRAS: observing with a 12.5” f/5 Newtonian telescope in a "semi-rural home site" in Lobethal, South Australia, she describes the object as being at "240X: Extremely faint, relatively large, round, 30” in size. With the UHC filter, the planetary appears bright. 480X: Faint, smooth glow throughout, with a faint stars [sic] on the NW and SW edges." Jenny also comments that "The skies here typically have a limiting naked-eye magnitude of 6.1," which would mean that she has an advantage over me: not only is the planetary better situated for her location of about -35d north latitude -- using my planetarium program and changing from my location to hers, at the time of culmination of the object, I calculate that it would be 32 degrees higher in her sky than in mine! -- but also MY naked eye limit toward Puppis, on 17/18 Jan. 2007, was somewhere in the range of about 5.5, and thus not nearly as high contrast as hers. Yes: there in Australia, using merely a 12.5 inch scope, perhaps the object is almost an easy find: I can understand how she can call it "bright".

'Skyhound' Greg Crinklaw, the astronomy software developer, has an interesting webpage about Min 1-18. He lives in Cloudcroft, New Mexico, with an infinitely better sky than even mine in mountainous California. Yet, he found in his 18" scope that the object was utterly invisible without the OIII filter. As he can use his large scope at a lower magnification than mine and yet have an exit pupil in range of the filter (which I cannot at the power needed to be able to see M1-18) perhaps the image contrast enhancement provided by the filter does indeed 'work'; yet I'm surprised he says that there was absolutely "nothing" without the filter. Yet, he was using 166x to find it "readily apparent". At this magnification, perhaps the object was simply too small to register clearly without making the background darker. I achieved best contrast, however, by using not a filter but rather by employing higher magnification and getting a larger image scale... but my exit pupil was usually smaller than the ones used by Greg. Even at his power of 430x, which he says just sustained the object in view, his exit pupil would have been about 1.1 mm (assuming that his scope is f/4.5 and that he used, say, a 4.8 mm TeleVue Nagler.) I was finding that the nebula could be most easily detected without a filter at an exit pupil of about 0.8 mm, at 323x. I wonder if Greg spent as much time as I did, cumulatively, testing all possible combinations: I must have tried 3/4ths of my oculars, and all my filters, over a total period of time of nearly 2 hours!

For the adventuresome, I have included a wide area finder chart that I made up, showing the close proximity of this planetary to the famous one "inside" M46. I also recommend trying the Deep Sky Browser page for M1-18, and creating one's own customized finder chart.

0.5 degree finder: upright, correct

• Link to Jaakko Saloranta's related observation of M46 and planetary nebula NGC-2438 by an 8" scope.

Abell planetary nebulae are now sexy. When I got rid of my old home-made telescopes in 2001 and decided to take a break from observing until I could get newer, larger equipment (which turned into a sabbatical of nearly 5 years) the Abell planetaries were not particularly well known, nor sought after by visual observers. Looking back at the resources I used to use in the late eighties, I find that absolutely none are mentioned in the otherwise excellent book "Observing the Constellations" by John Sanford; and I find only a couple of Abells -- galaxy clusters -- mentioned in the index of "Deep-Sky Wonders", a compilation of the monthly columns by the late Sky & Telescope writer Walter Scott Houston. Why were these objects overlooked? I think there are two main reasons: until very recently, few amateurs had taken pictures, and before the Palomar and UK sky surveys were on the Internet, images were largely unknown and obscure; and secondly: there has obviously been a huge leap forward -- even in the face of encroaching light pollution -- in the achievement of visual amateur astronomers. The natural tendency of many advanced hobbyists is to "break new grounds" and to push their senses to the boundaries of experience. With so many spectacular telescopes now in the hands of observers, coupled with the opportunity to "brag" (err...perhaps one should say, nicely, 'to share') experiences in the numerous Internet forums, the Abell objects (both the galaxies, and the planetaries) are becoming known at last, outside the community of professional astronomers.

Before I purchased my new C-11 and 10" Dob in the summer of 2005, I did not even know about the existence of the "Medusa" nebula. Somewhere in my perusal of star charts and software, magazines, and Internet discussions, I came upon it and found, to my surprise, that it was indeed plotted on my Wil Tirion-Roger Sinnott Sky Atlas 2000.0 (but under the listing from the Perek & Kohoutek catalogue of planetaries.) The object suddenly loomed in my mind as not merely one of countless obscure things I'd never seen, and probably wouldn't seek, but rather as a MUST-GET acquisition!

In the third week of January 2007 two events drove me at last into action. First, I happened to notice that the "Medusa" nebula was mentioned in the BBC magazine Sky At Night (Jan. 2007 issue, p. 50, in the "Stargazing Guide" under objects for "Large Scope"); and second, I received a nice email from my cyberfriend Jaakko Saloranta, a remarkably skilled Finnish deep sky observer, who had managed to spot the object at home in Rajakylä, Vantaa, Finland using his 8" f/4.5 Dob. He wrote to me that "Having had such great success with IC 405 which is usually considered some sort of a challenge I wanted to test something else. I found the spot [where] I thought Abell 21 was but saw nothing. Attached O-III filter, swept the region @ 60x... suddenly two very faint, elongated spots flashed in front of my eyes. I did this again and again until I was certain of what I saw. So, saw it but not really that impressive since the last time I bagged it with my 3" from Tenerife. Impressive was that I found it without any maps only with an idea of how to find it based on a mental image 3 years back."

As usual with most of my first observations of new objects, I did not prejudice myself by looking at a deep exposure picture. I examined only the careful drawing made by Jaakko, under his suburban sky with naked eye stellar magnitude limit of about 5.5 optimum. This would probably be slightly worse light pollution than the conditions I could expect on a good winter night at "my site" in the mountains south of San Jose. Jaakko's sketch registered only two unconnected patches; perhaps I could do better with 2 more inches of aperture and a higher elevation.

Depending on exactly what reference source is used, the Medusa nebula is given an official diameter measurement of approximately 12.5 by 10.5 arcminutes: problematical for visual observers, as it has a "mean surface brightness of 16.36 magnitude per square arcminute": this means that despite the visual magnitude figure of 10.2 (similar to many Messier objects) the Medusa is infinitely fainter to the eye, being spread out so much -- and consisting largely of the reddish radiation of ionized hydrogen.

Just after midnight on the morning of Tuesday 23 January 2007 -- the day I am composing this account -- I turned my 10" f/4.7 Orion Dobsonian reflector telescope onto the proper star field, not too hard to locate about 12 degrees to the NNE of the "Christmas Tree Cluster" (NGC 2264) in the neighboring constellation of Monoceros (one of winter's loveliest celestial delights.) Two fairly bright stars point right at the nebula from due south, about a half degree away: SAO 96935 (Mag 8.1) and SAO 96937 (Mag 6.6); almost equidistant on the northern boundary there is a distinctive arc of three stars (SAO 96941, Mag. 8.3; SAO 96929, Mag. 8.5; SAO 96924, Mag. 8.6); and just to the NW by slightly more than a half degree separation is a sparse 8th-magnitude open cluster, NGC 2395 (which, in a large scope, is not especially distinct due to the plethora of faint field stars in this rich region.) About 1.5d to the NW there is a large, faint nebula (LBN 891) that is an even greater challenge than the Medusa, and a little more than a degree to the south, there is an interesting faint cluster: Dolidze 26, adjacent to 4.9 Mag. SAO 96952: so, there is a lot to look for here, even if you fail to nab the planetary.

But. fail I most certainly did not! Expecting it to be enhanced by a filter, I had already installed my 2" UltraBlock (UHC-type) filter in a 42 mm wide angle 2" barrel ocular (too large an exit pupil, but giving me a chance to survey the entire scene all at once) [28.4x at a 2.4d FOV]. It was immediately apparent that the nebula was there; but I had to get my exit pupil situation to conform to my aging eyes, so I quickly changed to a 32 mm Plössl [37.5x. 1.4d FOV, 6.8 mm exit pupil]; but this particular ocular -- an Orion "Sirius" model -- has such uncomfortable eye relief, made worse with a filter, that I was immediately dissatisfied, and sought my better Orion "Ultrascopic" 25 mm Plössl [48x. 1.1d FOV, 5.3 mm exit pupil]: perfect! I recorded in my notebook that this combination gave me the best overall view and image brightness: the nebula was a big, distinct fuzzy "blob" festooned with innumerable, extremely faint, field stars. Taking out the UltraBlock filter, I could perceive the nebula but not nearly as distinctly: it seemed to shrink to half the diameter. I also installed my OIII filter and decided that it gave me even better contrast between the glow of the brightest part of the nebula and the average field background; and I could trace out the object's extent even better, though at a slight loss of maximum brightness, when I switched to my Orion Stratus 21 mm eyepiece, plus the OIII filter [57x, 1.2d FOV, 4.4 mm exit pupil], which is often my choice for high contrast, sharply clear views at moderately low power. Impressed almost to the point of gasping with pleasure, I gave the object my highest rating (four exclamation points: !!!!) and wrote, "With filter, almost like looking at a bright Messier object: spectacular and amazing!"

In my 'patented Waldee imprecision' I drew a couple of eyepiece sketches, not for accuracy but mostly just to check against a picture at home, later. The first one -- very crude -- was restricted to the bright central region (at left) but gradually I began to suspect that there was more to the nebula, and drew it again with the 21 mm Stratus, now showing a slightly irregular arc with densest portion approximately to the north (image at right); when I checked these the next morning against a good image found on the Net, I was ecstatic: for I had seen essentially the whole object, not merely the two disconnected "blips" picked up by Jaakko's smaller scope in a somewhat less dark sky. The first of many images that I found on the Net was this one by Alan Chen, done with a Meade 12" SCT: a stack of 20 four minute frames, with a color registration that suggests that, if it's accurate, there may be a significant oxygen component in addition to the hydrogen alpha (which is why the OIII filter seems to help the nebula visually.)

There are numerous excellent amateur images on the Net. I like these especially: a view in h-alpha light, registered during the full Moon (!) using a 1-meter Cassegrain telescope by Anja von der Linden; and a "collaborative effort between Dave Jurasevich and David Held, sharing data acquisition and processing tasks", achieved with a 12.5" RCOS Ritchey-Chretien. This particular picture is specially interesting because it shows the blue central star (16th magnitude) that I did not even attempt to try to pick up: was I too easily discouraged by its dimness? (It might possibly be detected with my C-11, judging from past experience with other planetaries.) Drawings of the object can shed different light on it than such amazing photorealistic images: you should see the work of Bill Ferris and Iiro Sairanen.

How difficult is this object to be able to see? Well, if we can judge from this report (registration required) by "AstroDawg" (the nickname Steve Gottlieb uses for the ASTRONOMY magazine online forum) of an observing session at Lake Sonoma, Ca. on 1/3/07, "in the finder I confirmed an earlier 80mm sighting of the Medusa Nebula (Abell 21) using 13x and OIII filter. This was not a difficult observation with averted vision." (Of course, some of us suspect that Gottlieb is not really human, but is probably a "Six Million Dollar Man" with enhanced cyborg-vision!) It was not clearly visible in my 9x50 finder but perhaps the prevalence of a lot of faint stars in the spot, plus some of the nebulosity, made its exact location look a little distinctly brighter than the surrounding region.

Finally, the most inconsequential question of all regarding this object: who the heck nicknamed it "Medusa"? I searched high and low on the Net, turning up various pages with fanciful astronomical monikers (such as this one) but none that carried a specific attribution.

0.5/2 degree finder: upright, correct

• My later report of detecting Abell 21 on 2/8/08 using a 4.7 inch (120 mm) aperture refractor.

• Link to Jaakko Saloranta's observation by means of an 8" Dobsonian scope.

Does "LBN 891" actually exist? I'm sure of it; I've seen it!

Yet, if you consult certain highly regarded star charts, you won't find it. According to friends who use the software, it is not included in the database of "Megastar"; and though it appears onscreen in "GUIDE", when you click on the object for information, you are told that according to the "Nebula Databank" put together by Eric-Sven Vesting, it is probably non-existent. (Vesting appears, my research indicates, to be an amateur astronomer and astronomical product salesman with astro-shop in Hamburg, Germany.) Yet, the object certainly shows up if you plot it by means of the Deep Sky Browser.

I viewed this nebula on the same occasion as the session that yielded my observation of Abell 21, the "Medusa" nebula, described above: after midnight on the morning of Tuesday 23 January 2007 at "my site". I had prepared a chart for the Medusa, using the Deep Sky Browser page. When I used that website to create a wide field finder chart for Abell 21, it showed also LBN 891, about 6 degrees to the NW of the Medusa. Placing my 10" Dob onto the field is easy to do as one merely locates three bright stars in a row, the nebula being slightly to the north of the middle star. These are, from east to slightly southwest in a line extending about 2d 22m, the following: 54-Lambda Geminorum (SAO 96746, a brilliant 3.6 mag); 51 Geminorum (SAO 96638, 5.3 magnitude: the central star of the three that is inside the southern border of the nebula); and 45 Geminorum (SAO 96535, 5.6 mag.) The nebula is a huge 2-degree patch extending north of the central star; it might show up best at low power in a rich field type scope in a very dark sky, aided by a filter. In my case, the sky brightness had some degree of light pollution, with an approximate naked eye stellar limit of perhaps something quite close to 6 or very slightly brighter; but the sky's transparency was exceptionally good at my high altitude, the weather being perfectly clear with high barometric pressure.

First I looked with my 42 mm wide field 2" barrel eyepiece (similar to an Erfle) which, in my 10" scope, yields a huge field of 2.4d, at 29x but with an over-large exit pupil. The glow was apparent though it was hard to distinguish it clearly from faint field stars that might confuse the observer. So I switched to a small exit pupil and higher magnification, settling on my favored Orion "Stratus" 21mm ocular, plus UltraBlock [57x, 1.2d FOV, 4.4 mm exit pupil], in the best range for maximum filter efficiency. A very distinct glowing patch was much more densely noted above the average background, and I did my best to draw a sketch. Judging from that, the area that was brightest was perhaps a half degree in diameter. Using the filter made a dramatic difference in its visibility.

I was satisfied, but the next morning at home, when I began to do research about the object, I became immediately perturbed. First, Jaakko Saloranta emailed me that Lynds 891 did not appear in his computer star chart program at all: he uses "Megastar", considered to be the ne plus ultra for data inclusion. I checked with another friend who has the Project Pluto: GUIDE; in version 7, LBN 891 is indeed plotted. But the text information stipulates that Eric-Sven Vesting doubts its existence! I sent him an email requesting clarification about his evidence and conclusion, and received this reply a few weeks later:

Dear Mr. Waldee,

you have reached the right person, but I must admit that i can not recall the [decision] I made 10 years ago. I have used the DSS (100 CDs) and the ''Atlas Galaktischer Nebel''. A deep CCD image with todays equipment should be able to solve the mystery [easily].

Clear Skies
Eric-Sven Vesting

The Deep Sky Browser page (link given above) for LBN-891 clearly shows its existence; so I downloaded all the Digital Sky Survey pictures to see what information could be perceived. As received, nothing but stars showed up; and there was a huge difference in the relative brightness of almost every one, making exactly similar processing impractical. But in my usual method, I applied iterative steps of contrast enhancement until the maximum apparent contrast range was evident to the eye; and I tested them in both positive and negative modes. The blue and red UK plates both showed nebulosity, the red plate appearing to have somewhat more density and distinction.

I next downloaded a one-degree region centered on SAO 96638 from the UK/Schmidt red plate, enhanced and cropped it, and adjusted the orientation and angle of my eyepiece drawing to have the same aspect for the purposes of this comparison picture. SOMETHING is there, indeed! The region of what I perceived as densest, brightest nebulosity, northeast of SAO 96638, shows up as being a grayish-whitish irregular patch in the heavily processed version of the red exposure, shown to the immediate right of the sketch.

The original Palomar Schmidt plates yielded some nebulosity, and the brightness situation seemed reversed, with MORE on the blue plate than on the red. How much of the difference is due to an overall gamma disparity; variable sky conditions; hypering, or other factors? One cannot know for sure from THIS limited experiment; and it might also be necessary to examine a very wide region of, say, several square degrees to see the nebulosity variations, not practical by means of DSS downloads. However, it tends to corroborate the value of color in the original catalogue, favoring the blue. How were these evaluated, and by whom: who was "Lynds"?

Now it was necessary for me to get some deep background on the subject. I first obtained the original Lynds catalogue, as published in 1965 in the Astrophysical Journal: you may get it in PDF form at this link. I read the entire paper by Dr. Beverly T. Lynds, in which she explains how the original Palomar sky survey plates were examined, with isophote maps of new nebulosity regions measured and marked, avoiding known ones (including recent planetary nebula discoveries by George Abell.) I noted particularly that she states:

There are many nebulosities having the same anomalous appearance on the Palomar prints. As their surface brightness decreases, their identity is lost, and a casual glance gives the impression that these objects mey be produced in the developing and printing processes. For this reason, some of the reject plates of the 48-inch collection were examined...The author is convinced that with a faster camera, of about the same scale, many more such nebulosities would be detected--objects of very low but relavitely uniform surface brightness in the red (103a-E) and blue (103a-O) photographs of the area.

Those 103 numbers refer to the old Kodak glass plate film emulsions used in the forties and fifties for astronomical pictures, standard types that were employed at professional observatories and used in the Palomar Sky Survey. I have looked at original 103 type plates, and earlier ones, at Lick Observatory and can testify to their detail and beauty if exposed after correct hypersensitization and in a very transparent sky. The online scans of the Digital Sky Survey really don't do justice to them, nor even to the large scale transparencies of the POSS that I have also examined at Lick Observatory back in the middle 1990s.

Furthermore, the files I obtained online were in GIF format, not the preferred FITS (as I don't have any really good FITS processing programs on my computer, the freeware stuff being of rather poor quality, producing images that look worse than the GIFs.) The Graphics Interchange Format (GIF) yields only 256 levels of luminance or color gradation, and according to this article, "is not suitable for photographs, half-tone images and other pictures in which you need a fine gradation of color rather than definite boundaries between different colors." It is lossless, but only because it contains a relatively small data set that is easy to compress and recover. My guess is that there is a definite loss of luminance detail at the low end, occurring at the first step of data scanning acquisition or maybe in the GIF conversion. Furthermore, Beverly Lynds examined the original plates as well as "rejects" in order to confirm some extremely faint nebulae. Perhaps persons who try to second-guess her professional work, but by using inferior online sources, are simply not able to gather sufficient accurate data.

As before in my work to confirm a nebular patch near Abell 7, discussed earlier, I found a situation where nebulosity showed up distinctly on the UK Schmidt DSS plates though poorly on the older Palomar ones. This could be due to a number of factors, including superior sky darkness in Australia and later developments in hypering and processing. So, since the nebulosity of LBN 891 does show up on both red and blue UK plates, I consider this a confirmation of Dr. Lynds' plotting of the object -- and it seems to be quite visible to the eye, at least at "my site" and under the conditions I've described.

The Lynds catalogue is quite well known, but who was the original investigator? It is Dr. Beverly Turner Lynds, now retired and living in Boulder, Colorado: not exactly a luminary in the astronomical world but a well known, respected, and solid researcher. According to a brief and slightly out-of-date biographical note found on this page: "Dr Beverly T. Lynds served as Assistant Director of the Kitt Peak National Observatory in the years 1976--1978, and in 1988-89 was the Scientific Assistant at the IFA, University of Hawaii. She [became] Program Director of the project SKYMATH [of the University Corporation for Atmospheric Research]. Dr Lynds edited the book Dark Nebulae, Globules and Protostars dedicated to Bart Bok." There are numerous links to her name on the web, but most are out of date. She apparently now lives in Boulder, and is presently retired; in 1987 she married astronomer Leo Goldberg, who was the director of Harvard College Observatory in the 1960s and became director of KPNO in 1971. Unfortunately, he died less than a year after his marriage, in Nov. 1987: see this article about him, which mentions his wife Beverly. There is also an interesting webpage article about rainbows, written by Dr. Lynds when she was with the UCAR. This webpage links to her well known "ATLAS OF DUST AND H II REGIONS IN GALAXIES": in numerous cases -- such as, notably, for NGC 5194, 157, 3527, and 6118 -- she has done sketches of galactic dust based on her examination of photographs, an interesting connection with the practice of visual astronomers in the era before photography.

After exhaustive searching I finally located a link to a picture of Dr. Lynds, taken at a conference. It is on the NASA Godard web page but the server was slow in responding so I could never bring it up. After trying numerous times over the space of several days, I got the page once and saved the picture. I placed the link in this article -- the website is here -- but afterwards I checked it numerous times and found that it was almost NEVER working. So I have cropped the larger picture of Dr. Lynds and include a "fair use" excerpted version of it here, since the government server doesn't seem reliably able to provide it.

Using what seemed to be the last known email address of Dr. Lynds, I composed a long email requesting background information on how she confirmed the faintest of the objects in her catalogue, and asked if she had a chance to compare the online DSS pictures with her recollections of the originals. Unfortunately, it was immediately bounced back to me by the mail server: "addressee unknown".

Investigators who would like to know more about these objects, and who are amateur observers, will find her original paper containing the catalogue to be a bit frustrating, for it is not ordered by the "Lynds numbers" that came later. The objects are listed in order of the galactic coordinates: thus the object now called "LBN 891" is, in her original, "200.10+11.99". In the paper, she gives its angular dimensions (120 by 120 arcminutes), area (2.76 square degrees), apparent color ("1" -- i. e., shows up on blue plate); relative brightness ("6" - barely detectable), and equatorial coordinates J1950. She also specifies that it is an "isolated region" and not associated with other nebulae, in the ID column. An ASCII text file version of the catalogue that conveys the current LBN numbers may be found here; this particular file is used by the GUIDE program for plotting, after precession to the current coordinate epoch. (I have also created my own page of Lynds bright nebula cross-references, adapted from the original catalogue, which you may access here.)

One other anomaly remains to be resolved: the issue of my being able to see the object better with a UHC type filter, even though according to the original Lynds catalogue data, it is considered to be more blue than red, ergo more likely a reflection than an emission nebula. Is it both? Sadly I don't seem to have recorded in my logbook a specific test with a SkyGlow LPR filter, which helps reflection nebulae (though it too will improve the contrast of emission objects: not a conclusive test.) A spectral analysis is needed, and one does not seem to be available to judge from the paucity of information about LBN 891 that turned up after two days' searching on the Net. This is truly an obscurity, and as such is probably worth investigation by advanced amateurs who'd appreciate a challenge!

UPDATE: My friend Jaakko Saloranta, who hasn't yet been able to look for the nebula (nor have I, since weather is now bad a few days after I spotted it), has done his own independent study of the Palomar red and blue plates, using heavy processing in Photoshop 7 (likely better than my cheap graphics editor called "PhotoStudio.") We seem to have come to the same conclusion: that the nebulosity does show up better on the blue than the red plates of the original Palomar survey, the ones used by Lynds; but he determined that this may also be the situation with regard to the UK plates, reversing my finding and, if correct, corroborating that the nebulosity has short (blue) rather than long (red) wavelengths. Jaakko has spotted regions that might stand out, including "a faint, irregular blob N from 51 Gem with (N-S) size about 0.7deg so quite large." He also opines that "it is there, but no wonder it is listed as 'probably non-existent' as it is so faint. This kind of high galactic nebulosity would get cropped from several lists, including the DSH's and MegaStar." He cautions me that my sketch may be inadequate and to make sure that one avoids being misled by glow from stars as "The area you sketched as the nebula, has several 10th magnitude and fainter stars that I'd consider to appear as nebulous with filters and small magnifications. Is this what you saw? No, I don't think so... The area, N/NE shows the same kind of 'blob' of faint nebulosity both in your sketch and in the POSS2/Blue plates. The size (I just measured it again from a Blue plate, centered on 9th magnitude GSC 1346-1012) is at least 60' x 55' so it pretty much covers the entire 60' x 60' field."

Jaakko has marked two regions: labelled "Area 1" (where I felt I could see nebulosity, which tends to be corroborated by the picture) and "Area 2" (which has a dense grouping of similar stars that could fool the eye into believing it was a nebulous patch.) His screen dump of the result, plotted by means of Megastar, is here. He suggested that "Area 2" would would serve as a test to determine what could be seen by eye, since this particular region does not show up on the Palomar plate as having significant nebulosity. If it looks clear by eye, while Area 1 still does look nebulous, "you've passed the test" and the nebulosity is really being seen. Thanks, Jaakko! And, for what it's worth, I've tried several times recently to test the assertion that filters 'create' spurious nebulosity under certain conditions, and as far as my equipment, eye, and viewing environment are concerned, I don't seem to perceive this as a repeatable problem.

0.5/2/4 degree finder: upright, correct

Messier 44, "Prasepe Cancri", is of course an object that is visible to the naked eye most anywhere outside a major population center, if one has learned the very rudiments of how to search for it. Why bother to include it in an article about particularly faint, obscure "fuzzies"? The answer is, of course, that for some perverse observers -- such as yours truly -- the object is an annoyance, because it makes it especially hard to see the galaxies that are along our line of sight, far beyond it!

I was not particularly conscious of the challenge of looking for them until the subject was recently brought up in an email I received from Jaakko Saloranta, a deep-sky observer who lives in Finland. It is a particular joy of his to make difficult observations: with VERY small optics; by naked eye; of extremely faint stuff. Since Finland is not exactly the Nirvana for year-round astronomy, he also observes in far southern climes, near the equator. His website contains numerous superb and accurate drawings, and lists of the many fantastic and obscure objects he is seeking, or has already achieved. We can start at his page featuring naked eye observations of M44, plus a wide field drawing done with a small refractor. Jaakko tells me that he sometimes spends hours making his detailed star field sketches, carefully scaling, plotting, and placing each visible star. My sketches are often laughably inaccurate, of use -- sometimes only vaguely -- to me later at home for checking something on a photograph. Jaakko's drawings, however, are often so good as to be useful as REFERENCES.

When I learned from him that, now, some advanced observers were making a special project of 'sweeping up' the galaxies visible in the interior region of M-44, I jumped at the opportunity to do so myself. Since getting my C-11 and 10" Dob in the summer of 2005, both scopes giving me a leap in limiting magnitude compared to my old 8" instrument, I have been attempting to see how faint I could go with them, primarily with small angular diameter, faint galaxies. I've reached about 16.3 magnitude or so with the C-11, and perhaps somewhere around 15.4 to 15.6 with the 10".

The problem is, of course, that "visual magnitude" is still not a well defined and universally controlled parameter. We have inherited lots of flawed magnitude measurements from the days of the visual astronomers whose work was compiled into the NGC; and recent 'photographic' galaxies, found only on deeply exposed plates done by large observatory telescopes, often have no visual magnitude rating. There are general conversion factors that may be used; but much adjustment is often required. The larger the object of a given visual magnitude, the harder it is to see with a telescope: because the light is spread out over a wide area. Well, then: why not use "surface brightness"? There are arguments against that, too: especially in relation to galaxies. So, let's just be somewhat imprecise, and generalize that galaxies fainter than a nominal 14th magnitude are indeed very dim and difficult to see. They don't look much better in a 20 inch scope than a 10 inch one: just specks of light, with very little detail seen, if any. Every time you increase your telescopic aperture by an inch or two, you see more... and more... and more of them. But, the only real satisfaction is just being able to check them off, one by one, and take some glum comfort in that repetitive task. As far as getting a real sense that you are staring at an isolated, distant, unapproachable "island universe" which MIGHT have intelligent creatures, planets, and astronomical wonders: you don't get that by seeing, with averted vision, a speck of light that is not much more distinct than a "floater" inside your own eye.

This is, then -- I have to admit -- the end result of a galaxy-quest in the region of M-44. I do it because I have a constant, gnawing craving to observe Galaxies Almost Too Faint to See®. (Perhaps I should write to Meade or Celestron to see if they'd like to use that slogan.) I do it for the same strange reason that I once collected 13,000 classical Lp's. I do it following the same impulse that has now led me to buy almost 10,000 compact disks (my friend Rich once made a face and grimaced when I told him about my latest purchases: "Waldee," he spat derisively, "you collect Mozart CDs by the YARD!") I do it because... perhaps because of a childhood potty-training deficiency (as a Freudian astronomer-psychiatrist might assert.)

I have only recently begun the project of going through the "nearly nothings" that comprise the galaxies in the immediate coordinate region of M-44. I've only been at it for part of one observing session, using my "backup" telescope (the 10" f/4.7 Dob), not the preferred GOTO C-11 that can be aided by a star chart to position itself closely to a desired target, and which has much less tendency of light scatter from the bright stars of the cluster. The Dob is, comparatively, a drag to use; and after an hour and a half of struggling to keep it just on a particular field, one is totally frustrated and exhausted. I'd rather do this with the C-11 and will, as soon as the weather permits.

I shan't do all your work for you. I intend here merely to list the galaxies that I am currently trying to spot, down to somewhere in the range of 16th magnitude visually (though some are rated only photographically.) You may make up your own chart using the Deep Sky Browser, as I did, and go to each of the objects in the links below to get their coordinates and whatever pertinent information is known about them (in some cases, very little.) [NOTE: See updated sections below; I've changed my mind and have produced a detailed chart given at the end of the article, which you may download; and have observed almost all the objects plotted on it. -- 3/27/07]

Since M-44 covers such a large expanse of sky -- about 95 arcminutes angular diameter -- it was difficult to download the entire object by means of the bits and pieces necessary using the Deep Sky Survey pictures; the one shown above was produced by NOAO/AURA/NSF, and doesn't show the faintest objects. I have made up a deeper image, here, based only on a 45 arcminute diameter from the DSS resources. There are galaxies way beyond that which are worth seeking; four show up in the immediate interior near the center of M44, which I have highlighted somewhat by subtracting the red plate data from the blue plate data of the UK2 survey picture, after making careful adjustments of the contrast of each picture. This diminished some of the star image data; the galaxies may appear a bit more distinctly by this means. I suggest that you create as large a chart as you can, such as this one I've linked to in the Deep Sky Browser. Zoom in until it has plenty of detail. It might not necessarily have all the labels required, so you must do some further detective work. For instance: on my first try, the edge-on spiral UGC-4526 didn't show up in the chart; I discovered its existence later, and went back to the Deep Sky Browser and hunted specifically for it.

On the early morning of Tuesday 23 January 2007, starting at midnight, I began the struggle to see some of these objects with my 10" Dob. The first thing I had to avoid was as much light scatter as possible, since some of the bright stars in the cluster range from 8th or 9th to 6.5 magnitude. Immediately I rejected the use of one eyepiece: my Orion "Epic" 3.7 mm, which has off-axis reflections if stars get slightly outside the FOV. But, I needed high power to be able to restrict the field, get as many bright stars as possible out of view, and distinguish faint, narrow angle objects. I found myself using a 6mm Plössl plus 2x "Shorty" Barlow [400x, 7 minute FOV, 0.65 mm exit pupil] , which worked quite well, maintaining a dark reflection-free background. By this means I was able to verify NGC-2643, which I rated as "VVF, near invisibility but just barely seen." NGC 2637 was even more difficult. I had to try to judge the exact angle relationships and positions with respect to the star field, but when I looked right at the expected spot... nothing. Finally after much frustration I allowed the field to drift across my eye, several times, not moving the scope until the nearby stars were well outside the eyepiece. After several tries, I decided that the galaxy was seen: just barely, at the threshold: "VVVF". Then I went for IC-2388, which was discovered by Edward Barnard. It rated only my inconclusive remark: "possibly. Ext F! Averted vision."

I moved to the western edge of the cluster and had no special trouble locating the somewhat brighter NGC-2624. I am dismayed to have to tell you that according to my notes, these objects required 1 hour 30 minutes elapsed time to locate and to claim to have been barely perceived. At this point I had at least one more relatively obvious object to pin down: NGC-2625. But, I was so fatigued and frustrated that after ten more minutes of struggling, going back and forth from high power eyepiece view to 9x finder, and to the chart, that I just collapsed! It was useless; my brain had deteriorated to jelly, and I began to have trouble focusing my eyes. At least, I may have gone to the visual limit of the 10" scope under the present sky conditions (perhaps NELM of 6th magnitude, on what I consider a "good" night at my site in the mountains.) But, it was time for a break; a snack; and to put on a different symphony. I took a much needed ten minutes off, and relaxed...

This project will have to wait for a night with the C-11. My difficulty with NGC-2625 was that the chart I'd prepared had the galaxy's isophote right at the edge, showing absolutely no field stars for triangulation. It was too faint just to pop into view without knowing precisely WHERE to look for it.

How do my 'betters' fare? Here is a good example, taken from a recent post made by Steve Gottlieb to an Astronomy Magazine observing forum (registration required.) I quote it in part:

Beehive Cluster galaxies: Yes, there are a number of faint galaxies hiding among the bright stars of the Beehive (M44). Bill and I confirmed our observation of 8 of these elusive galaxies. Five have NGC numbers, 2624, 2625, 2637, 2643, 2647) and were discovered by Albert Marth using a 48-inch f/9.4 reflector from Malta (see http://www.klima-luft.de/steinicke/ngcic/persons/marth.htm to have a look at this behemoth scope). With some effort we also identified CGCG 89-056, IC 2388 (discovered by E.E. Barnard) and UGC 4526. The easiest of the lot are the pair NGC 2624 and 2625 on the west end. NGC 2624 was described as "fairly faint, small, round, 25" diameter, weak concentration. A mag 15.5 star is close SW. Brighter of a pair with N2625 located 3.2' ESE. Situated on the NW edge of the Beehive cluster." My notes for NGC 2625 read "faint, very small, round, 15" diameter. Smaller and fainter of a pair with N2624 3.2' WNW, though the difference in brightness appears less than the 1.4 magnitudes listed in catalogues." This was using 280x in my 18-inch (7mm Pentax XW).

A lot more experience, and more aperture, tell the tale. But, I'm not finished yet! Below is a table of the ones that I have plotted. When THOSE are finally acquired, I'll go for more! In the column of "Designations" the galaxy names are hyperlinks to the appropriate Deep Sky Browser page so that you may easily obtain coordinates and more data.

IC-2388 Boy, is this one faint! Further attempts to confirm it visually have been "iffy". On 3-17-07, with my GOTO C-11 telescope, I zeroed in precisely on the position, confirmed with a printout I made of the chart given at the end of this section. I wrote that it was detected but "seemed to be about 30 arcseconds to the W of the position charted by TheSky version 6 -- can this be right?" Or, was I suffering from an illusion, since the galaxy is SO faint? (The program GUIDE shows IC-2388's declination as being 20 seconds less than the value given in TheSky: could this account for the discrepancy, which I might not have precisely judged by eye?) On 3/16/07, I tried at 1am using the C-11 and gave up by 1:20, writing "No! Sky transparency, seeing getting worse." But on 2-24-07, using my 10" Dob, I felt I could definitely see it, using an earlier chart prepared from the Deep Sky Browser page, writing that it was "barely detected, at threshold using averted vision, 1:20AM, 10mm [Orion Sirius] Plössl + 2x [Orion Shorty] Barlow" [240x, 12 min FOV, 1.05 mm exit pupil]. So, counting the suspected viewing of 1/23/07, perhaps I can rack up at least '1-1/2' sightings, and consider this one accomplished. One really comes away from this experience with increased respect for Barnard's acuity, as well as a fatalism about experiencing dark skies similar to those of more than a century ago.

ZWG 089.056/PGC 24284 On the same date as immediately above, 2-24-07, with the same scope and magnification, I believed that I detected this object, and wrote that it looked like a "Fuzzy, near stellar-spot, fluctuating". On 3-17-07, with the C-11 telescope, it seemed to be somewhat more definite: "Something there -- very amorphous, low surface brightness. 9mm Expanse [311x, 12 min FOV, 0.9 mm exit pupil]; saw various 'lumps' with 6mm Expanse [466x, 8 min FOV, 0.6mm exit pupil]. On the night of 3/15/07 using the C-11, I wrote that at 10:02 pm "I got it! 3.7 mm [755x, 4 min FOV, 0.4 mm exit pupil]. Zeroed in on field. AV [averted vision]: oval faint blob, EEF." The seeing was excellent; an hour earlier I had split HR 3701/STF 1338 (a nearly equal-magnitude double, measured at 1.0" separation in 1999.)

ZWG 089.062/PGC 24335 On 3/15/07 at 11:33pm, I saw it with the C-11, writing in my logbook, "Took an hour! Tried 15mm, 9, 6, 10+2x Barlow, 7.5 epcs, the 9.5 mm gave faintest *s [294x, 10 min FOV, 1.0 mm exit pupil]. Along a line from GSC 1395:1841 (11.8 mag) past GSC 1395:2631 (15.4 m) for another few seconds. Fades out to inv." Then, at 11:45 pm: "Got it more consistently with 7.5 mm [372x]." Finally at 12:05 am, "Best w/6mm [466x]. Almost steady now, a general glow < 1' dia, sometimes get the faint * next to it [GSC 1395:2931, 14.6 m]. I also have an observation logged with the same scope on 3/17/07 at 1am: "May be a few arcseconds to E of a ~14m *." So, I'll consider this object observed.

PGC 24400/UGC 4526 Same date, scope as above. "Not too hard. F, cigar shape but not distinct; used averted vis., 9mm Expanse [311x, 12 min FOV, 0.9 mm exit pupil]; ~15th mag * in it?" This is one of those ambiguities of the Guidestar Catalogue that I'd need to know more about to figure out for sure. GUIDE shows a nice narrow isophote plot, with a green dot near the very center, which is identified as GSC 1395:2000, mag. 13.8, "non star: 2". Yet, TheSky v. 4 identifies it as "Non-Stellar 3" at mag. 14.9! And, that program does not show a galaxy isophote, nor plot the galaxy at all. To confuse the issue further, TheSky v. 6 plots the galaxy, but shows in the EXACT center, a star labelled GSC 1395:2008, mag. 14.3! On the previous session of 3/16/07, using the C-11 I wrote that the galaxy looked like a "Faint spindle ~1' thin to left of faint * GSC 1395:2029 (14.8 m). With 7.5 [372x] VF but pretty well seen, AV." I believe this confirms that I did see the galaxy visually, more than once: so, again, call it observed.

IC-2390/NGC 2643/PGC 24434 According to the information page for this galaxy on the NGC/IC Project, quoting Dr. Harold G. Corwin, "NGC 2643 = IC 2390 This identity, first suggested by Reinmuth, was taken up by RNGC. The object was found by Marth in 1864. Correcting his position by 18 seconds of time and 11 arcmin leads to IC 2390. The IC object matches Marth's description, and there is no other object in the area (the east edge of the Beehive) that would fit better." But on the same page there is a longer commentary by Malcolm J. Thomson, pointing out other difficulties with Marth's observations of three "new nebulae" that same night. (This page cannot be directly linked here, but you may find the information by surfing to this link and typing in "IC 2390" in the dialogue box for NGC/IC designation.) The DSS picture provided shows only ONE galaxy at the current accepted coordinates, and it clearly has an edge-on depiction as seen from the Earth, with a center bulge. Steve Gottlieb's observation is given: "17.5": very faint, very small, round, 15" diameter. Located 1.2' NW of a mag 11.5 star on the eastern side of M44. Several brighter stars in the 22' field at 220x." I am confident that I have now seen it. My own observation, C-11 telescope on 3-17-07, states that it was "EF! [extremely faint] Small spot w/9mm [311x, 12 min FOV, 0.9 mm exit pupil] & maybe 7.5 barely [Orion Lanthanum ocular, 372xm 8 min FOV, 0.8 mm exit pupil]. Better seen while slewing scope slowly across field." My eyepiece drawing shows the galaxy and three stars in the field that agree, correcting for my scope's image orientation, with the DSS picture. Done!

NGC-2624, 2625 On 27 January 2007, using my 10" scope and a chart made from the Deep Sky Browser, I had observed NGC 2624, definitely. But I gave up at that point, my chart not covering the guide stars at the edge of M44 near 2625. On 3-17-07, I was using a superior and more detailed chart -- given below so that you too may download and print it -- and found both these galaxies with relative ease using my C-11. 2625 was a "Very small round patch, fading in/out with 9mm [311x, 12 min FOV, 0.9 mm exit pupil]." 2624 "seems larger, can see straight on and hold, 9 mm."

NGC-2647 This galaxy is slightly outside the "official" boundary of M44, about 40 arcminutes to the SE of the exact center of the cluster. This galaxy was spotted by me with the C-11, as above, and described as "something involved with ~13.5M * -- hard to tell shape and PA. 9mm, and possibly seen w/ 7.5 mm" [Orion Expanse and Lanthanum oculars, operating specs given above.] TheSky version 6 shows that the star "involved" is GSC 1396:93, 13.5 mag. But, GUIDE gives two separate measurements: 12.98, and 13.52, and calls it a "non star". TheSky 4 says that it is "13.0" and plots it 36 arcseconds to the SW of the galaxy, while it is shown in the exact CENTER of it, in GUIDE. Go figure...at any rate, I am pretty sure I saw it, so I'm considering this one done.

Moving to the immediate region OUTSIDE of M-44, I secured observations of some nearby galaxies included in my downloadable chart:

PGC 24431/UGC4532 SE of center of cluster, this galaxy is somewhat larger than the other PGC objects, rated at 16.2 magnitude, 1.3 by 0.2 arcseconds, seen edge-on. On the date above with the same equipment, I observed it and wrote, "Definitely seen w/9mm while slewing across field slowly. Larger nebulous patch, varying in visibility," (I meant larger than previously viewed galaxy PGC 24522, given below.) An anomaly to be noted, when using my chart, is that the program which produced it did not use the correct angular diameter coordinate and showed it as being round. GUIDE, and other software programs, plot it as having an extreme edge-on and narrow shape.

PGC 24522 This faint galaxy is about 58 arcminutes to the E and slightly S of the center of the cluster. It is rated at 16.4 (photographic) and at 0.5 by 0.4 arcminutes diameter. Could I possibly see this? Apparently, yes. At above observing session I wrote, "SAW it! Suspected with 15mm Expanse [186x, 21 min FOV, 1.5 mm exit pupil], confirmed w/9mm. By sweeping slowly, perceived oval with decent clarity and definition, but VVF." I don't know how you would calculate a precise visual magnitude for this object, but it would be one of the faintest galaxies I've ever seen with my C-11!

PGC 24188/CGCG89-53 This galaxy is located about 51 minutes from the center of M-44, to the W and slightly S. It is a 16.1 magnitude (photographic) galaxy, with a diameter of 0.6 by 0.3 arcminutes. My logbook of the same session as above states, "Saw, inverted vis., VF * (14th M) which might be on the SE periphery?" This star would appear to be GSC 1936:1740, 14.8 according to TheSky 6, plotted just off the center of the galaxy to the SE but within the isophote; however, GUIDE shows it nearer to the center and rates it at 14.3. Perhaps the brightest region of the galaxy is not the exact center of the longer axis, to the eye. This could indeed be suggested by these pictures, shown in this NED link. And, in the POSS picture (shown as a negative) there is a very faint star next to the longer axis of the galaxy which does not appear to be plotted in the GSC: maybe this is the star that I saw? (The only problem is that if the picture is pole up, the star would appear to be to the NW, not the SE: did I make a mistake when I wrote my description? Possibly.)

PGC 24407/CGCG 120-021/MCG +04-21-013 This galaxy is shown on my downloadable chart in the upper left (NW) corner; its magnitude is 15.2p, and the diameter is a round 0.6 arcminutes, with a surface brightness of 13.8 mag/sq arcminute. My notes state that on 3/18/07 at 3:10am (with the C-11) it was a "Very slight glow between 2 *, one to N fainter - dark sky now, completely fogged in toward Gilroy!" The pertinent Deep Sky Browser page shows something perplexing: it plots the galaxy to the west of the stars I describe, even though the DSS picture shows it between the stars (the northeastern one being GSC 1398:1741, 12.4 mag, the southwestern one being GSC 1398:1959, 11.9 mag.) I cross-checked the object in GUIDE, and found that it too placed the galaxy at the same incorrect spot, about 5 arcseconds to the SW, not between those stars. So I then downloaded the image of CGCG 120-021 from the NED search engine, and confirmed that -- yes! -- I was precisely right in my visual description; the software and website were wrong. (Little discoveries like this tend to increase my own sense of confidence as an observer, I'll admit.)

A galaxy shown in my downloadable chart that was NOT seen during this session was PGC 24315. I wrote "No. Tried slewing across region but not detected." Another questionable one is NPM1G+19.0185, which is -- as you will note from my chart -- very close to ZWG 089.062/PGC 24335. Frankly, I suspected it to be the SAME galaxy (though I didn't feel entirely competent to make that claim, as it is an object from the respected Lick Observatory Northern Proper Motion [NPM] program, and one of the authors of that catalogue, Arnold Klemola, just did me a nice favor last week!) It is plotted by my computer program TheSky 6 at a slightly different location than PGC 24335; but GUIDE does not show NPM1G+19.0185 at all, though it plots PGC 24335. I viewed this region carefully, and saw only the latter object, not the allegedly different "NPM" galaxy at a supposedly nearby location. Then, while researching the matter to edit this webpage, I used the NED search engine and typed in both "NPM1G+19.0185" and "PGC 24335" successively: and came up with the same object name information table and picture! Finally, after writing up the following week my observation report of the obscure galaxy PGC 17232, I learned to use Hyperleda more effectively, and confirmed that -- yes, indeed -- it IS the same object. In perusing the documentation file for the J2000 version of the NPM catalogue, I learned from Dr. Robert Hanson's explanation that "in June 2003, after an overlap comparison with NPM2, we re-calculated the NPM1 transformation (B1950 to J2000) using an improved algorithm." A complex process was used to transform the coordinates; "the new J2000 NPM1 is accurately on the J2000 coordinate system at the 0.1" level or better." That suggests that the larger position error of the spurious location of the galaxy in TheSky is due, instead, to another problem, common also to the database used by the Deep Sky Browser of Mikkel Steine. Perhaps the original year 2000 version of the NPM1 is in use, not the revised and improved version, or some file conversion process has caused a rounding of number values. Indeed, innumerable other small, faint galaxies and nebulae in many star chart programs are not properly cross-referenced and reconciled, and may prove confusing to those of us who see the discrepancies onscreen, differing from what we can see in our eyepieces and in sky images.

In fact, in the chart below, I used the photographic or total B-magnitude for the obscure non-NGC or IC galaxies (with visual magnitude ratings) that I obtained from Hyperleda. If you click on the links, you will often get a different rating (usually fainter) on the database used by Mikkel Steine's Deep Sky Browser. Do these small discrepancies make a real difference? For visual observers, using instruments where the galaxies are just at the threshold of detection: possibly. This could explain why I can see galaxies that are often shown by my star chart program as being "16.3" or somewhat fainter; another catalogue might list them at "15.7" or slightly brighter. Ah, me...

I revised the 'Magnitude' column values on 3/30/07, using a variety of sources: the Steinicke Revised NGC data; the NGC/IC Project; and my own conversions from the total-B or other magnitude given by the Hyperleda search page for the object, processed with a modified version of the Javascript Visual Magnitude Calculator by Matt Oltersdorf. His program -- found here on the net -- as originally written has a cutoff of 16.0 magnitude; I have modified it by changing the source code, leaving the edited file on my own hard drive. The results are interesting and probably not entirely accurate, but in comparing certain galaxies with published v and p magnitudes, it can come close. The galaxy visual magnitudes I have so derived are marked with a tilde (~) to indicate that the value is approximate.

Here is my new chart for locating galaxies seen through M-44 and in the immediate region; the round outline -- 70m diameter according to this particular software program; others say as much as 95m -- shows the outer "official" boundary for the star cluster, and the field width is about 2d 32m horizontal, 1d 26m vertical: