Sometimes, I suspect that amateur astronomers are often "bipolar personalities" since so many of us are buoyed up by excitement over our new fancy optics, cameras, and accessories -- and then let down horribly by the sky conditions, the struggle to find and see objects, and the defects we inevitably find in our gear (see my related article about obsessive- compulsive behavior and astronomy.) Apologies are due to my gentle readers for my failure to resist exploiting the tendency to make an allusion and affect a rather "cheesy" tie-in and introduction to the discussion of one of the sky's most interesting bipolar nebulae, NGC-7026, nicknamed "The Cheeseburger".

Approximately one out of ten known planetary nebulae share the morphology of this object, caused by the asymmetric expansion of the hot gases ejected from a nearly-exhausted star. Sometimes rather than forming an even spherical surrounding shell, gas accumulates into lobes; then high temperature surfaces emit UV light, illuminating the tenuous plasma clouds. The bipolar lobes of NGC-7026 are better discerned by eye, surprisingly, than by conventional photographic film. The Digitized Sky Survey plates, using the Palomar Schmidt and the UK Anglo-American Telescope, are all so overexposed that the details of the nebula are lost: it has taken on a rather solid rectangular appearance in almost every one of them. Only the UK infrared picture showed anything different. I used a cropped 8 arcminute region containing NGC-7026 at the center, and took the libery of "airbrushing" it by various means, using a graphic editor, to create a simulation of the way the nebula looked to me in my Celestron C-11 telescope, which is the resulting image shown immediately above. A more accurate depiction, in color, was imaged by Carl Burton, Jr., using his Celestron C-14 to reveal details never seen by the dark-adapted human eye, sensitive only to faint shades of gray when viewing such a dim object. If you compare Carl's picture -- or one taken with a Celestron C-9 by Dr. Richard Jacobs to an example done by a large aperture observatory scope (in this case, the 62 cm classical Cassegrain at the Saint Véran High Altitude Observatory, you will see a progression of imaging detail that culminates in the remarkable filamentary structure captured by the Hubble wide-field camera. But, if you contrast the Palomar Schmidt picture with a drawing done by Prof. B. Mauclaire with a 17 inch aperture telescope, you'll confirm that regular chemical photographs don't do it justice.

NGC-7026 was discovered by S. W. Burnham in 1873, using a 6-inch refractor. The original NGC description stipulated that it was "bi-nuclear" indicating that 19th century visual observers obtained essentially an accurate impression. It is not a faint, inacessible object to any diligent amateur who has, surely, an 8 inch or larger scope (being relatively bright at magnitude 10.9); certainly it can be seen in smaller scopes under dark skies. Because of its diminutive overall size (29x13 arcseconds), the surface brightness is a high 8.4 magnitude per square unit of area.

I have observed it a few times in the past sixteen months, the last being just before midnight on Thursday, 26 October 2006 at "my site". In the C-11 scope, I found the nebula to be "bright and fuzzy" using my 15 mm Expanse eyepiece [187x, 21 min. FOV, 1.5mm exit pupil], not requiring a filter for detection or identification. Using higher power with a fairly large aperture scope can reveal the dark lane, as my 6mm Expanse ocular could do with the C-11 [466x, 8' FOV, 0.6mm exit pupil]. Or, one may use an UltraBlock (an 'ultra high contrast' hydrogen line filter) or an OIII type: which will, with appropriate exit pupil to keep from severely extinguishing the light, help to enhance the faint dark narrow region in the bifurcation of the lobes, for which an amateur astronomer dubbed it "the cheeseburger" due to its alleged resemblance to buns surrounding a meat patty: a nickname that I have to confess that I find very trite!

On his "Skyhound" pages, software developer and observer Greg Crinklaw has posted a very good article on NGC-7026, including an eyepiece finder chart. Observers with larger telescopes than mine have contributed very detailed descriptions, such as this report on Jeff Burton's Astronomy Blog, in which color was detected using a 16 inch aperture instrument; and Mark G.Birkmann's 'dissection' using a 40 inch scope.

Incidentally, the tireless and dedicated observer might wish to move approximately 77 arcminutes to the east, past the open cluster NGC-1369, to find another bipolar planetary nebula: Sharpless 1-89, or PK 089-00.1, located at 21hr 14.1min RA, and +47deg 46min dec, a much fainter but somewhat larger object (14.5 magnitude, 44x29 arcseconds' diameter.) I was unaware of it the times I had viewed nearby NGC-7026, but shall -- during the next season that Cygnus is favorably positioned -- look for it with my GOTO scope. There are scarcely any amateur observations posted on the Net, but I managed to locate a good one in the Yahoo PNeb group by Ted Forte, who found it to be a "ghostly faint object" though viewable by means of an OIII filter. This planetary's moniker is "The Moth"; could it be hovering there, attracted by the 'smell' of the Cheeseburger?

And now, if you'll excuse me: I'll bring this discussion to an end. For some reason, I've just been overtaken by a gnawing hunger...

This fascinating pair of interacting galaxies is listed as No. 140 out of the 338 items included in the Catalogue Of Peculiar Galaxies compiled by astronomer Dr. Halton C. Arp, one of the great mavericks in the professional field of observational cosmology in the 20th century. A "denier" of the Big Bang theory, he was marginalized at the Carnegie Institution, and left after 29 years as a very celebrated astronomer. Not only did he depart the Palomar Observatory in California, he also left the United States altogether, turning to the Max Planck Institute in Germany in 1983 to continue his research. He theorizes, based on his numerous observations of interacting galaxies and close pairs that have different redshifts (including some with apparently anomalous connecting bridges) that the redshift differences are explained by redshift quantization, or a tendency for redshift values to accumulate around certain multiples. This violates the tenets of the standard cosmological model, of which one of the leading exponents is the Palomar astronomer Dr. Allan Sandage of the Carnegie Institution (whom the present writer had the privilege and honor to interview for his Horsehead Nebula history study.) Sandage was a protege of Edwin Hubble -- a short article written about his great mentor is found here -- and is celebrated for his work in measuring the Hubble constant. But, if Arp is correct (probably to be determined sometime in the future) the standard model would essentially have to be abandoned.

Naturally, cosmologists in the mainstream largely dismiss Arp's arguments as being based on optical illusions, or casual axial alignments: an interesting (sympathetic) summary of Arp's views may be found on this web page. My own initial (admittedly very amateur, poorly informed, and casual) look into the controversy, back in the 1980s, led me to suspect that the grainy, fuzzy photographs published by Arp in his book "Quasars, Redshifts and Controversies", obtained frequently at the very limit of resolution of the great earth-based optical telescopes of the time, proved relatively little. Isophote plots done by primitive computer scanning and enhancement looked unconvincing to me. Later Hubble telescope images of high resolution have not confirmed the claims, failing to give certain vindication to Arp and his supporters: the skeptics have not been silenced.

There is, in fact, an interesting parallel situation, regarding what mainstream scientists call "pseudoscience", in the whipped-up alleged controversy about "The Face On Mars" and other assertions of anomalous artificial objects on not only Mars but also the Moon, and other celestial bodies. The leading amateur-science proponent is the famous propagandist Richard C. Hoagland, a brilliant debater and polemicist. Hoagland is dismissed by almost all mainstream astronomers (with the exception of a very few, such as Dr. Thomas Van Flandern, a thoroughly professional astronomer -- Ph.D. in astronomy, from Yale, specializing in celestial mechanics -- who worked largely at the U. S. Naval Observatory.) The real difference, though, is that Arp comes directly from the professional mainstream: like Sandage, he was once an assistant to Hubble, and is a respected academic; while Hoagland (who holds no degrees in science -- or any other field as far as one can determine) is working entirely outside of the professional field as an "independent investigator", a difficult task and one that immediately sets him at odds with degreed professionals. My prediction is that both Arp and Hoagland will ultimately be discredited, the respectable though odd theories of the one, and the far-out speculations of the other, being overturned as accurate, incontrovertible evidence accumulates.

And, still: there will be those who will, forever, insist otherwise. The healthy existence of many of the world's most ancient creeds proves this. As a personal friend of mine, a professor of neurophysiology at NYU once observed, "there are Zoroastrians parading with signs near my office, in Greenwich Village."

Yet, I confess that there would be nothing more entertaining in my experience, than observing anomalous Arp galaxies while listening to the passionate discursions of Hoagland on "Coast to Coast AM". Unfortunately, on the night at "my site" that I scanned the field containing these galaxies, there was no such confluence of iconoclasts, and I had to listen to some quiet chamber music instead. I was using my 10" Orion SkyQuest f/4.7 Dob, which I often employ in the fall and winter when the dew point is dangerously close to the outside temperature, virtually guaranteeing a fogged corrector plate on my more powerful C-11. On 18 December 2006, I recorded in my logbook that the Arp 140 pair consisted of "an elongated patch blending into a stellar, bright nucleus on the western side, using my 9 mm Expanse ocular plus 2X Barlow [267x, 15' FOV, 1mm exit pupil]." Steve Gottlieb, a renowned amateur observer who has looked at more than 7000 of the NGC and IC objects (and whose reports are all collected here) has reported that with his 13.5" telescope, 274 is "moderately bright, small, compact, [with] very small bright core. Forms a close pair with N275 1' SE." That galaxy, 275, is described by him as being "moderately bright, fairly small, diffuse, [with] even surface brightness." And the esteemed deep sky observer Tom Polakis posted a message to the Yahoo group "amastro" in December of 2004, in his investigation of bright galaxies in Cetus, describing Arp 140 as "Nice galaxy pair, NGC 275 is larger, 1'x0.5', with a broad concentration, NGC 274 much smaller, nearly stellar with a small surrounding circular haze, but much higher surface brightness, could be confused for field star at 85x."

But, here's something very odd. Gottlieb, Polakis, and I all found the elliptical galaxy NGC-274 (to the west) to have the bright, distinct nucleus, with the other one, NGC-275 the spiral to the east, having the more even surface glow (east is to the left in the picture above, west to the right, north to the top.) It's nice to find one's own spontaeneous, unprejudiced observations confirmed by such experts. However, using a 20 inch aperture scope, much larger than Gottlieb's 13 or my 10, Kent Reeves came to the opposite conclusion. Was he right, and the extra aperture makes the difference; or does he merely have his galaxies reversed? Writing in his article "Fuzzy Spot, Cetus" on p. 4 of the December 2003 SACNEWS of the Saguaro Astronomy Club (downloadable here as a PDF), Kent opines that "This nice galaxy pair was seen in the 20" with the separation being obvious, but they are touching. 275 is somewhat small, somewhat faint, and has a gradually brighter middle with a very bright stellar nucleus which really jumps out. The elongation is uncertain. 274 is somewhat small, somewhat faint, and slightly brighter in the middle with no nucleus seen. There is a star to SW, but no other stars nearby." You may confirm for yourself that I do have the galaxies labeled correctly in the picture above, by checking with the chart for the Arp pair on the appropriate page of the "Deep Sky Browser", and by going to the NGC/IC Project DSS Images selection page, and clicking on "NGC 274 Data". And, yes: there is a star to the SW, as Kent states: it's a very faint one, somewhere between 14th and 15th magnitude. So, I'll have to keep an open mind about this until I get a chance to see the pair in a very large aperture scope; but for what it's worth, Polakis was also using a 20" scope -- and disagrees with Reeves about the characteristics of each galaxy.

NGC-274 -- the elliptical galaxy, discovered by William Herschel in 1785 -- has a small angular diameter that it is rated at 1.5 by 1.5 arcminutes; 275 -- the spiral, discovered by John Herschel in 1828 -- is 1.5 by 1.1 minutes. 274 is the brighter of the pair, at 11.8 magnitude to 275's rating of 12.5. According to Cullen, Alexander, Green, et al., NGC-275 (a "late type spiral") is interacting with 274 (an "early type system"), evidenced by hydrogen gas observations, showing the existence of a tidal tail from 275, extending far beyond the pair: implying the beginning of a merging of the galaxies some 1.5 billion years ago.

You may read about a very interesting amateur project, by Dennis Webb, to photograph the Arp galaxies, on his Internet page at this URL. His gallery includes a digital image of Arp 140 that is scarcely less detailed than professional observatory pictures.

Finally: diligent observers who work in a darker sky than mine, and with a larger instrument, might wish to search about 11 arcminutes to the NNW of Arp 140 for the galaxy shown at the top picture (produced from the POSS1 blue plate, cropped to a region of about 15 arcminutes.) That galaxy, the spiral NGC-273, is much fainter and, sadly, I could not see it with my 10" scope on the pertinent night. It is rated at 12.9 magnitude, but at a dimension of 2.2 by 0.7 minutes, it has a lower surface brightness. I expect that I might have just detected it in my C-11.

This "inconsequential" galaxy in Eridanus (which is perhaps much more interesting than it might seem at first glance) will not be well known to many visual observers, save those with large aperture scopes and an appetite for faint 'nothings'. A type Sbc II galaxy, NGC-1247 is a nearly edge-on spiral that had been discovered by William Herschel during sweeps with his 18 inch metal alloy mirror reflector telescope -- then by far the largest practical instrument in the world, his 48 inch instrument, made in 1789, being so unwieldy that the great observer seldom used it except for specific observations to check results obtained by the smaller scope.

I sought out the object during the night of 18 December 2006, while taking a "tour" of Eridanus objects chosen by Sue French for her December 2005 S&T "Deep Sky Wonders" column. The galaxy should  be on p. 11 of the Tirion Sky Atlas 2000:  but it's not plotted there. Since I've seen it with a 10 inch aperture scope in a somewhat light- polluted sky, I am sorry for this omission, for it was easier to detect than certain other objects that Tirion chose to plot, such as Sharpless 2-205 and many other extended nebulae that have been included. I happened to have no other charts with me, so it was lucky that the small finder in Sue's column was (barely) legible under my red light. However, covering a fairly large field, the guide stars were reduced to about ONE single half-tone dot, making it extremely difficult to discern them and to compare with the view in my upright, correct finder. But persist I did, and managed -- despite the nasty frigid wind gusts at "my site" -- eventually to acquire it.

"'Flat' galaxies are among my favorite observing objects," Sue writes. "NGC-1247 is one of the entries in the Revised Flat Galaxy Catalogue by Igor D. Karachentsev and his colleagues of 4,236 galaxies that appear at least seven times longer than wide." The reference figure for the galaxy's size is 4.6 by 0.6 arcminutes, making it narrower even than the famous "spindle galaxies" in Draco and Sextans. The outer edges of this faint object will therefore be difficult to detect in a relatively small telescope, compared to long exposure images or the view in a "giant" Dob. In Sue's 10 inch scope, in her "semi-rural" sky, the galaxy seemed to span only about 3 arcminutes; it was even shorter in mine, of an indeterminate length due to light glow from Hollister and Santa Cruz intruding: only really a "speck" just above the background, using my 9 and 6 mm Expanse oculars [133x with 29' FOV, and 200x at 19' FOV, respectively.]

I have found various figures for the galaxy's brightness. Steve Gottlieb states that it is 12.5 magnitude, the figure given by Sue in her article. But, the RNGC value is 12.7, while one of my software star charts stipulates 13.4; the Deep Sky Browser page for the object lists it as being 13.5 magnitude (photographic) with a surface brightness of 14.3 magnitude per square arcminute. Let us merely agree that it is very faint. In fact, I suspect that it is at present the faintest galaxy that I may have seen, so far, with my 10" scope at "the site", though I can go slightly deeper using that scope under less light pollution -- and jump more than a full magnitude fainter with my C-11, which has higher contrast due to its enhanced coatings. The view in an 8-minute cropped image taken from the POSS1 blue plate (shown above) can scarcely suggest the tenuous sight I beheld, writing that it was "just past imagining: v-faint!"

Those observers whose star charts or computer programs fail to plot NGC-1247 may use the Deep-Sky Browser page for this galaxy to create wide and narrow field finder charts.

Not a challenge object, having a bright central star (9.4 magnitude, not naked eye by any means, but visible in an 80mm scope) and somewhat distinct surface brightness (12.6 magnitude/sq min), this planetary nebula in Taurus can be used to test the effect of nebular filters, and to determine if your optics have a significant tendency to scatter light. Spurious glow around the central star can mask the gaseous shell of the nebula.

As one might imagine, this too is a William Herschel discovery (13 November 1790), using his 18 inch telescope (can that have been the most productive discovery instrument up to modern times?) He listed it as one of the "nebulous stars" he had found, stating that because the glowing shell was faint and even, there could be "no surmise of its consisting of stars". His polished "speculum" mirror apparently had no trace of any light scatter, for he observed that other stars in the region were "perfectly free from any such appearance." Thus we may judge that his hand polished mirror and magnifying lenses must have been of exceptional quality.

I, however, do tend to notice traces of light scatter in my Dobsonian scope, especially around stars brighter than 5th or 6th magnitude. At 10th M, the scatter is not objectionable and usually not detectable; nor did it diminish NGC-1514, which I observed at "my site" at 2:45 am on Friday, 27 October 2006. My 10" Dob gave a good view of the 2-arcminute shell of gas surrounding the star, which I recorded enthusiastically as being "great! Almost as good as down south [referring to a private dark sky site with 7th magnitude naked eye stars, more than 200 miles south of San Jose.]" The object was at the meridian, only ten minutes before transit: perfectly situated for the best possible view at my latitude. With my 21 mm Orion Stratus eyepiece [57x, 74 min FOV, 4.4mm exit pupil] plus my O-III filter I could see "much detail around crisp central star: bright spots in nebulosity." And, at the earlier viewing in a darker sky, five days earlier, I had remarked that there were "lots of details w/o filter; fairly bright disk with sharp edges using O-III, with 7.5 mm Lanthanum [160x, 18 min FOV, 1.6mm exit pupil] and 9 Expanse [133x, 27' FOV, 1.9 mm exit pupil]. With 7.5, saw uneven surface with distinct bright spots." The drawing made by means of a view with an 18" aperture Newtonian telescope by Finnish observer Iiro Sairanen isn't really far off from my own perception with a 10" scope, in a very dark sky.

If you are a member of the Yahoo Planetary Nebula group (which I highly recommend!) you may do no better than to search for a fascinating post to the group about NGC-1514, written by Andrew James on Friday, 1 November 2002, entitled "Re: NGC 1514" (viewable only by members.) I won't quote it here, robbing him of the privilege to have his words read in their entirety. It's one of the most informative discussions about the object on the Net, with respect to amateur observing techniques (though the old link given to a Tom Polakis drawing is now defunct.)

This surely is a nebula that should be seen in color, with all possible enhancements afforded by Big Science. But, surprisingly, no image of NGC-1514 has been published by the Hubble Space Telescope, apparently. A diligent search of professional catalogues yielded a few arcane isophote plots, not very interesting to the amateur, and some variations in the processing of Palomar pictures (all deriving, probably, from the blue POSS1 plate, which I used, above, for my 10-arcminute field picture.) The best one found is surely this semi-professional picture, made with a 20 inch Ritchey telescope, used at the Visitor's Center at Kitt Peak for amateur programs. This digital image was captured in LRGB mode with SBIG ST10XME CCD camera and color filter wheel, accomplished by Adam Block of NOAO/AURA/NSF: as one can see, the primary radiating wavelength is the greenish hue of doubly- ionized oxygen (making this object a prime candidate for employing an O-III visual filter.)

No need to provide a finder chart: it has been done for us all, by "Skyhound" Greg Crinklaw, who has produced a very nice webpage about NGC-1514, which is -- incidentally -- nicknamed, appropriately, "The Crystal Ball."

There are many individual components of this gigantic star-forming region in the winter Milky Way, located about 17 degrees NE of the great nebula of Orion, M-42. I can no longer remember when I first saw this amazing vista, but it is likely about thirty years ago, soon after I acquired a good 10" telescope and a wide field eyepiece. But, unfortunately, nebular filters were not available to amateurs. Yet, with the reduced light pollution at "the site", which then offered regular experiences of 6th magnitude or fainter naked eye stars, night after night, the pale, spread-out nebula was nevertheless detectable, though not even remotely like a photograph (such as the excellent one shown here, done by bay area astrophotographer Jim Molinari with his Tele-Vue Genesis f/5 refractor on hypered Tech-Pan, a 20 minute exposure, contributed by him for our "Eyepiece" software program. )

Yet, even with the encroachment of hundreds of thousands of residents, and perhaps thousands of new businesses, in the complex extending from San Jose south to Gilroy, I was able to see the Rosette in its glory, at "my site", in September, 2005, using merely a 3-inch refractor: thanks to the modern nebular eyepiece filter. More on the observation will follow, below.

England's John Flamsteed -- the first Astronomer Royal -- recorded the initial sighting of the open cluster at the heart of the Rosette, about a decade before the opening of the eighteenth century (during the same year that he observed the planet Uranus, but mistook it for a star, leaving its true discovery as a planet to William Herschel, 91 years later.) But Herschel himself claimed discovery of this same cluster, in 1784: so now you have the answer to an astronomy parlor game question: "What two English astronomers claimed discovery of the same two objects?" And William's son John compounded the blunder by 'discovering' the cluster all over again in 1830, also making a small error in its position. That these great early figures were so inaccurate is entirely understandable, given the lamentable condition of celestial catalogues, the scarcity of printed resources, and the lack of reliable communications. We who use the Internet so casually, conveniently, and smugly today might remember that our "easy pickings" of most of the world's astronomical history and data are but a recent phenomenon. (Yet, for all that plethora of information: I can't find a definitive answer of who took the first photo, though I have a distinct memory of seeing what might likely have been the earliest one, printed in a late 19th century issue of "Knowledge", a British science magazine still kept in the library of the Lick Observatory at their Santa Cruz collection, and perused by me in 1989 while I was studying the history of the Horsehead. It might well be likely that Max Wolf was the photographer; either he, or Isaac Roberts -- or maybe Barnard himself.)

Yet though the bright hot blue stars -- the engine that drives the stellar formation and nebulosity -- were now know, recognized, and plotted, the nebula itself was still unperceived, and would continue to be for many decades. It was only when the observer Albert Marth employed the mighty 48-inch "speculum" telescope constructed by Lassell, in 1864 under the clear skies of the isle of Malta, that the visually- brightest region now catalogued as NGC-2238 become identified; then comet-hunter Lewis Swift published his discovery of a nearby segment of the nebula, now given the number that predominates for the whole of the object -- NGC-2237 -- after spotting it in a 4.5" aperture refractor in 1871. The eagle-eyed Edward Barnard finally traced the outer extent of the nebulosity with a small refractor, in 1883.

Why did not the earlier, extremely patient, skilled observers detect the nebula? My hypothesis is that the problem was due mostly to the narrow field of view of the ancient oculars used by professional astronomers, often the "monocentric" type with an apparent field of only 20 degrees, or even less. Secondarily it is the extremely long focal length of professional achromat refractor telescopes, designed to have a high focal ratio of about f/19 to minimize chromatic aberration. With such an instrument and ocular, nothing of the nebula could be seen. (For instance, the Harvard College Observatory's great refractor -- at its installation the largest in the world -- would deliver over 500x with a FOV of only slightly more than 2 arcminutes with a "half inch" ocular. And, the Rosette nebula subtends 80 arcminutes angular diameter on its wider axis!) Only the relatively short focus small telescopes made by Herschel -- such as his portable six-inch aperture reflectors -- had a chance of showing an appreciable field of view, followed later by "comet seeker" refractors of short focus, of the type used to such great advantage by S. W. Burnham, Swift, and Barnard to find many original discoveries of nebulae and galaxies that had been overlooked, being too faint and extended to show up to the fixed professional observatory refractor instruments. Then at last, late nineteenth century photographers began employing "fast" portrait- camera lenses, with blue-sensitive plates that were hypersensitized by a "pre-flash" of light, in four hour exposures: and finally the sky's famous nebulae gradually became known -- and seen -- as they have been up to recent times (when space telescopes, and imaging with narrow bandwidths, have revolutionized our perceptions of these amazing objects.)

Today, the "standard" view of the predominantly red hydrogen wavelengths of the Rosette -- popularized in traditional color photographs made after the 1960s -- are being supplemented by radical new depictions, showing also the color wavelengths radiated by oxygen and sulfur. And cutting-edge amateur astronomers are making a big scientific contribution, such as the remarkable work of Richard Crisp of Castro Valley, California (who lives only a few tens of miles from the author of this article.) His digital images, done not far from the very heart of the silicon valley, such as this example in the light of Ha, OIII and SII, rival the work of great predecessors from the world's largest observatories -- and even surpass them; yet he uses a small, precision refractor! Isolating the pertinent wavelengths with sharp bandpass filters, he can alleviate the light pollution of his near-suburban yard.

The same concept, applied by makers of accessories for visual astronomers, helps us to see the Rosette, at least in dim shades of gray that our dark-adapted eyes can perceive, with even very small telescopes. In September, 2005 at "my site", I eschewed using my large C-11, or even my 10" Dob, for a short night of observing to test a new toy: an Orion ST-80 f/5 achromat refractor, which cost me under $200. Such a modest device is truly a 'toy' compared to the fine instrument used by Crisp, or the superb astrograph (AstroPhysics 155 mm) employed by Chuck Vaughn for his stunning monochrome image of the Rosette Nebula in H-a Light. Indeed, the cheap mount that I cobbled together for the ST-80 -- which I discuss in this article -- cost me as much as the scope tube itself, a mere fraction of the price of Chuck's optics.

The key to seeing such a faint, extended, huge-diameter object as the Rosette (almost three times wider than our view of the apparent diameter of the Moon, spanning 90 light years with a size some 65,000 times that of our own solar system, as described in this article) is to use a nebular filter.

I was the "Product Development Coordinator" of the Orion company back in the 1980s when the first of their narrow nebular bandpass filters, the "UltraBlock" model for isolating the general lines of hydrogen, was introduced, and was given the task of testing it in an urban setting. I found to my great delight that I could see the faint "Crab" and "Owl" nebulae (discussed earlier in these articles) even in nearly the exact center of San Jose, California, amidst industrial, residential, advertising, and street lights -- and with merely a 4" aperture "Astroscan" telescope. I bought the filters for my own use, and later -- after leaving Orion and becoming an associate of Dr. Jack Marling of Lumicon, developing the now discontined "Lumiview" computer program as a means of instructing observers how to use his filters -- I purchased Lumicon O-III and H-Beta filters. I now own a new Orion O-III filter as well, plus their "SkyGlow" light pollution rejection filter. I could never imagine an observing session without them: to read my opinions and suggestions, consult this webpage I've composed, based on an original 1997 article that I have recently updated.

The filters I used for my test observations of the Rosette nebula with my 80 millimeter aperture Orion "Short Tube" refractor were the UltraBlock (same as the 'narrowband nebular filter" in this picture), and the OIII (the oxygen-III filter, transmitting only the wavelength radiated by doubly ionized oxygen near 500 nanometers: the so-called "forbidden lines" of radiation that can occur in the near vacuum of deep space.) By alternating these two filters with a low-power view of the Rosette, I was able to appreciate the object even though the light pollution at "my site" had washed out naked eye stars fainter than about 5.5 magnitude. I used a 20 mm Expanse ocular [20x, 3.3d FOV, 4 mm exit pupil] plus either filter, to showcase the entire nebula against 'clear space'. I also experimented with both lower and higher magnification to try to see details, such as the dark lanes, bright rims, and the beauty of the central star cluster (without any filtration.) I also tested the object in my wife's little 4" aperture rich-field Orion "StarBlast" reflector scope, which yields a somewhat brighter view but not necessarily a more aesthetically pleasing one (due to the coma of the fast simple Newtonian mirror optics.) I decided that the view with the smaller aperture refractor was really quite a bit more pleasing, and spent a significant portion of an hour just feasting my eyes...

While the UltraBlock is perhaps the ideal filter for the object, it was also enhanced by the OIII significantly, the background sky becoming even darker, and the lanes more distinct: but the extinguishing of light might be somewhat too extreme for some viewers, especially those whose eyes are not profoundly dark-adapted.

Later, on 18 November 2006, I had an opportunity to repeat the observation with the 80 mm scope, now being used as a piggy-backed low power finder for my more powerful C-11. The latter instrument has such a narrow field of view that while one can see the whole of the central star cluster NGC-2239 (which looks more spectacular and sparkling than any photo or digital image!) , one can't get any 'sense' of the whole nebula. I was able therefore to alternate "closeup" and "whole" views by changing between the eyepieces of the refractor and the SCT. Then I recorded that the "Rosette is best with 80 mm scope, using either a 20mm Expanse, or 25mm Ultrascopic [16x, 3.3d FOV, 4.9mm exit pupil], plus O-III filter." The picture here -- taken from the eyepiece simulation of the Rosette in our free telescope program -- employed Jim Molinari's picture to show how a nebular filter can enhance details of the object in a light-polluted sky.

Finally, I'd like to commend to your attention (if you enjoy reading details about such astronomical objects as much as I do) the following webpage: an extremely detailed article about the separate components of the nebula, with all the coordinates and discoverers, is found here, prepared by Haluk Akcam, a superb reference for advanced study of the object.

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

This interesting little planetary nebula in Draco is a rather obscure object, though it's been known since 1788, when William Herschel found it during sweeps with his 18 inch telescope. The object is nearly round, with a measured diameter of 31 by 30 arcseconds; thus, even with a moderate aperture telescope it can be seen as a disk; yet the 19th century description in the New General Catalogue was "very faint, stellar." The planetary has an appreciable surface brightness of about 12th magnitude per square unit of area, though the visual magnitude rating is 13.4: since that light is spread evenly only over a small area, it's much brighter to the eye than many 13th magnitude galaxies would appear. I did not consider this a "challenge" object; but other observers apparently do, for it's included in the article Deep-Sky Objects for June under the sub-heading "Objects for Larger Telescopes (16-inch & larger) Challenge Objects", published on the website of the Amateur Astronomers Association of Pittsburgh in their very useful Objects of the Month pages.

I found no amateur sightings of the central star; not surprising, since it is rated at 19.4 magnitude. To observers with scopes about the same size aperture as mine, it is small and featureless, as described by my friend Jaakko Saloranta in Finland (whose article includes an eyepiece sketch.) His drawing, made with an Orion 8" Dob, is similar to what I saw at "my site" with the C-11. Using a larger 18" aperture Obsession Dob, Bill Ferris -- accompanying his drawing, showing more stars -- records that the object "appears as a 40" diameter foggy glow. The central star, estimated at 20th magnitude, is understandably not visible." Yet, Bill's view illustrates a much more tenuous "edge", fading out into the background, compared to Jaako's view; could it be due to an optical illusion, since Bill claims that the object is about 10 seconds larger in diameter than it is known to be? (Based on his many outstanding observations in Finland, I'm beginning to think that Saloranta observes in a fantastic sky!)

I wish I could claim that my own view was even as definite as Bill's; however, no doubt the residual light pollution at "the site" in the Santa Cruz mountains made my observation much more difficult. My logbook records that on the evening of 18 October 2006, the planetary was "barely seen with 6 & 9 mm Expanse eyepcs [467x, 8 arcmin FOV, 0.6 mm exit pupil, and 311x, 12 arcmin FOV, and 0.6 mm exit pupil, respectively]" which both yield exit pupils so small that filters extinguish the light excessively. I found that it was seen "best w/15mm Expanse [186x, 21 arcmin FOV, 1.5 mm exit pupil] using the UltraBlock filter; OIII not as good." (I think the reason for this is that with a 1.5 mm exit pupil, the OIII filter is slightly out of range, causing too much extinction.)

The deep-sky maven Steve Gottlieb, who has attempted to view by eye all possible NGC and IC objects, discerns more detail with his larger telescopes: with an 18" it was a "beautiful view at 322x, appears moderately bright, fairly small, round, crisp-edged, ~30" diameter. The rim is slightly brighter giving a weak but definite annular appearance"; in a 17.5" scope "at 220x without filter appears fairly faint, round, fairly small. At 105x using an OIII filter the planetary is bright and compact with crisp round edges." But, oddly, Steve Coe (using a 13 inch Dob) had a quite different experience, reporting that the planetary was "A low surface brightness nebula and the UHC does not help. Not much."

The POSS1 blue plate (above, cropped to a 10 arcminute diameter region) just shows some of the nebular variation; better views of this are seen in an excellent amateur image by William McLaughlin, who obtained a superb color rendering, clearly showing the faint central star, with an AstroPhysics refractor; and this 'semi-professional' picture by Adam Block (NOAO/AURA/NSF) using a 20-inch Ritchey telescope at Kitt Peak.

Galaxy challenge! I want owners of giant Dobs to find this one.

I frequently run into "Dobsonian chauvinism" in Internet and usenet forums, particularly those dealing with observing faint, obscure objects. Large Dob owners can sometimes be a bit condescending to users of "small SCTs", the category that one of them relegated my instrument to, compared to his own big scope, implying that mine would not show up very much of interest to "advanced observers." Well, indeed!

But, as a happy and satisfied user of a Celestron C-11 GOTO scope, I have been able to benefit from the precision with which I am now able to locate objects -- described by me in this article -- after a year's work enhancing and fine tuning my process. Thus, with care I am now able to locate and identify objects that I missed, when I used a 17.5" Dobsonian scope at "my site", relying on the conventional star-hop method. In addition, I 'stock' my laptop computer with several programs and databases, as well as spreadsheets of objects, enabling me to cross-reference catalogues in the field, if I wish to take the time to verify the identification of something obscure.

It was by this means that I definitely verified my accurate acquisition and observation of a very small, faint galaxy in Triangulum: not the fare of typical deep-sky visual observers, and without even a SINGLE report about viewing it found on the Net after a diligent search. The only information I could locate was based on professional catalogues, derived from optical and X-ray images.

I was observing galaxies in Triangulum at "my site", using the C-11 connected to my laptop computer to locate faint objects. The night of 29 October 2006 wasn't very favorable to the north, preventing me from finding even a trace of the galaxy "Polarissima Borealis" (NGC 3172) due to San Jose light pollution; that night I could barely find Comet 177P/Barnard, which had faded to 11th magnitude, though I was able to spot some faint Principal Galaxy Catalogue objects near it, in the range of 14th magnitude, which encouraged me to try a darker region of the sky. Apparently the transparency was better than usual, at 3,400 feet altitude: for in short order I located quite a few faint ones after midnight. They were so difficult that I took the extra step of writing down the distances and estimated brightness of field stars so that I could go back later, at leisure, and verify my observations. Yes: I stipulated that what my computer star chart program showed as "PGC 74060", a 16th magnitude galaxy, was seen approximately "30 arcseconds from a 13th mag. star" (which turned out to be GSC 2308:593, 13.2Mv), using my 7.5 mm Lanthanum eyepiece [373x, 8 minute FOV, 0.8 mm exit pupil]. I stated that the galaxy was "barely seen" but that I could move away from it and return, and get it again: as is my wont to make sure observations aren't imaginary.

A later search for the galaxy using another computer program gave me the reference number for the KUG (Kiso Ultraviolet Galaxy) catalogue, from which I was at last able to use various online professional database managers such as NED (which refused to recognize "PGC 74060" as being a valid identification, despite the fact that my expensive star chart program used it. However, that was a correct ID, according to the HEARSARC search engine for the Principal Galaxy Catalogue, which did turn up the object correctly, displaying both optical and x-ray images.)

This galaxy is given no visual magnitude rating. The photographic (blue) magnitude is 16, and the apparent size is a "tiny" 0.6 by 0.2 arcminutes. There is no redshift listed on on the NED information page, so I can't even calculate its approximate distance. Just about the only thing I could find about it is that the galaxy is included in the "KISO survey for ultraviolet-excess galaxies [XIII]" by Takase and Miyauchi-Isobe, published in 1991. The 2-Micron All-Sky Survey photo, right, shows no significant detail that wasn't recorded on the POSS1 blue plate I used for the 9-arcminute diameter picture, above.

Masochists with large Dobs who would like to "show me up" may use the appropriate Deep Sky browser page for the object to generate charts: see this link. I'd love to be able, some day, to read a report on the Net of a visual sighting that is on the order of detail and precision that is typically found in a writeup by the "two Steves", Coe and Gottlieb. Any takers?

Someday I might like to write an article entitled, "The Astronomical Errors of a Genius". It would be an accounting of the blunders made by a fascinating fellow who discovered 100 objects, making him a very prolific observer in the days of visual astronomy, though not quite in the league of John Herschel. Truman Henry Safford was his name, and according to his biography, he became well known even as a child: for even by the age of 6 this boy from Royalton, Vermont demonstrated bewildering powers as a "lightning calculator" to an amazed public. "He could mentally extract the square and cube roots of numbers of 9 and 10 places of figures, and could multiply four figures by four figures mentally as rapidly as it could be done upon paper." By the age of ten, Safford was described admiringly by the Harvard professor of mathematics Benjamin Peirce as being blessed with "powers of abstraction and concentration rarely possessed at any age except by minds of the highest order."

Graduating from Harvard at age 18, Safford stayed at the university, working at its College Observatory (of which he became director for one year, in 1866), largely occupied in the compilation of position measurements (done, of course, visually with the great 15" Merz refractor.) His most celebrated post was director of the Dearborn Observatory, commencing just after the conclusion of America's civil war. His studies of new "nebulae" (many now known as external galaxies) were interrupted by the Chicago fire! Afterward he prepared many latitude and longitude charts for the Army Corps of Engineers, and became an astronomy professor in 1876 at Williams college, which awarded him a Ph.D. in mathematics two years later.

A Daguerrotype photograph, taken when he was about 9 years of age, illustrates his early fascination with astronomy, showing him in a pose with a telescope and a sextant. Yet, for all the brilliance and mathematical facility of the man, as an adult astronomer he was not exceptionally precise. While at Harvard, Safford discovered two new alleged star clusters that were described so convincingly that Dr. Dreyer was persuaded to add them to the New General Catalogue: but all that can be seen for one of them -- NGC 2189 -- is a pair of nearby field stars (a "random clumping" of some stars has been found nearby, but is not yet confirmed as Safford's object due to the imprecision of the NGC listing); of the other -- NGC 2198 -- Dr. Harold Corwin Jr. writes "I see nothing in the field on the POSS1 prints that looks like a cluster. Perhaps a visual observation can turn up something." Later, Safford did use a powerful 18.5 inch refractor to locate about a hundred new objects, largely "nebulae", as Dearborn Observatory director during the years 1866-68: these were published too late to be included by Dr. Dreyer in the New General Catalogue of 1888, but were added by him to the supplemental Index Catalogue, released in 1895. IC-200 (the galaxy pictured above, in the POSS1 blue print, cropped to about 12 arcminutes' field width) was one of them.

However, of the total of 106 objects that Safford and his assistant Aaron N. Skinner contributed, 3 were entirely spurious. Corwin writes of IC-200, "The galaxy 34 [seconds] following the IC position is probably too faint to have been seen by Safford, and the description does not match in any case. The object 2 minutes of time following does match his description, and a 2 min digit error is more likely to be made than a 34s error." (I have examined a very deep plot of the region of IC-200 by means of the pertinent Deep Sky Browser page, as well as with software programs. No significant galaxy seems to be within several arcminutes of IC-200; but there is of course FGC 242, a very faint -- photographic 17th magnitude -- and thin 'spindle' galaxy slightly south and somewhat over three minutes to the west, or preceding the galaxy IC-200. It could surely have been seen in an 18 inch telescope; but it is impossible to imagine from Safford's description -- 'pretty bright, pretty large' -- that this was what he was reporting.) Other mistakes of the mathematical genius include those made in his observations of IC 1012 (with a 2 minute mistake, plus a small error of declination), as well as IC 1026 (equivalent to NGC 5653) and IC 1030 (equivalent to NGC 5672), both with a spurious +1 minute RA increment.

Ironically, the Dearborn Observatory's 18.5" Clark refractor was considered so accurately mounted, aligned, and calibrated that it was used for several series of extensive parallax studies of stars, binary systems, and asteroids, up to modern times.

I was utterly unaware of all this history on 29 October 2006 at "my site", whilst I looked at faint galaxies in the region of Triangulum. At about 2 in the morning I used my computer program to move my C-11 scope to IC-200, after having looked earlier at faint KUG 0156+31 (discussed above.) After some small difficulty in spotting the galaxy, I experimented with various oculars to get maximum contrast, confirming that I had seen the object shown onscreen in my star chart, and at the appropriate position angle, writing in my logbook that IC-200 was "Barely seen with 12.5 Lanthanum [224x, 13 minute FOV, 1.3mm exit pupil], and "better in 15 mm Expanse [186x, 21 arcminute FOV, 1.5mm exit pupil]. Very low SB [surface brightness]."

I've scanned the Net, and posts to deep sky observing groups on Yahoo forums, and haven't found a single amateur visual sighting report about this obscure galaxy; not even Steve Gottlieb -- who has looked at about 7,000 of the NGC/IC objects, has published one. IC-200 appears very small -- an apparent 0.6' by 0.5' -- and has a photographic magnitude of 15.2, with a faint mean surface brightness of 13.6 (in magnitude per square arcminute): dim, but definitely within range of an 11 inch instrument with high quality optics, such as mine.

One of my older planetarium programs (which shall be nameless, as I am extremely dissatisfied with the offerings of this particular software developer, and don't wish to publicize any "plugs" for their products!) oddly seems to have a peculiar internal database: calling up IC-200 from the menu of objects results in an "empty field" right in the center of the screen; yet IC-200 is plotted and labelled, but some 7 arcminutes following. This is far more than the 2 arcminute error of Safford; what gives? I'm glad that their later version -- which I use to control my telescope -- has apparently reconciled the mistake, so that the galaxy does show up onscreen in the proper place, when the telescope is pointed at it.

I am in fact quite certain that I did not mistake IC-200 for the galaxy shown to its right, in the POSS plate displayed above, using about the same FOV as my 12.5 mm eyepiece. That small, narrow galaxy -- FGC 242 -- is a nearly edge-on object included in the Revised Flat Galaxy Catalogue by Karachentsev, and is very likely too faint for my telescope: indeed, it has no published visual magnitude. I increased its brightness a little bit in the picture shown at the top, fearing that it would not show up at all on most monitors in the original contrast range of the Palomar plate.

In the perhaps unlikely event that this discussion of mine will stimulate somebody to look for IC-200, there is an easy way to obtain wide and narrow field charts, using the appropriate object page in Mikkel Steine's Deep-Sky Browser website.

Aaargh!  My astronomy laptop and office desktop computers are stocked with hundreds of megabytes of "software I love to hate," which has kept me busy most of this afternoon, the last day of 2006, running back and forth, and to the Internet, to try to track down these two objects and find the catalogue cross-references and other pertinent data. One of my programs -- the main star chart that I use to control my C-11 telescope, which I refuse to name -- has the most cobbled up cataloguing system imaginable, with databases all out of both alphabetical and numerical order; position errors; odd syntax; and sometimes incorrect position angles and diameter plots. Another program happens to be the only one I have that enables one to search for the stars of the Bonner Durchmusterung; but it stubbornly refuses to do so when I give it a proper BD name, emitting a scary error message and crashing. A third program refuses to recognize the normal syntax used for identifying the Sharpless nebulae, which are plotted even on my "entry level" printed star chart, Wil Tirion's Sky Atlas 2000.0. And, websites are often no better. The Sharpless Catalogue online uses only galactic coordinates, which have to be converted to equatorial ones since those are used by all amateur astronomers; and it produces unrecognizable, confusing maps without guide stars. SIMBAD recognizes standard Sharpless numerical designations, but NED does not; nor does it make sense of Lynd's Bright Nebulae Catalogue IDs. At one point I had no fewer than three PCs running, with two printed star charts laid out before me, augmented by two observing books. At long last I pieced together a coherent assemblage of information just for this short "Fuzzy" entry about these two faint, tenuous nebular patches in the constellation of Auriga: which took me a total of about 25 times the period of minutes that I studied the nebulae at "my site" with my 10" Orion f/4.7 Dobsonian telescope.

As I wrote earlier in my entry for the Horsehead nebula, "before dawn's twilight on 1 October 2006, a pitch-black sky background (afforded by deep fog in the valleys below) enabled me to see the dark [Horsehead] cloud with full-on direct vision, a clear view -- not much inferior to a good monochrome photograph -- that took my breath away!... probably my third-best view at the site, out of more than three dozen occasions studying the object." That gives you an idea of the conditions I found, at 3,400 feet elevation in the mountains, with ground fog around me, cutting off artificial light pollution from the myriad of streetlights and signs in almost all directions. It was a dark sky to dream of! About an hour before I viewed the Horsehead, I looked at these two Sharpless nebulae, large clouds of hydrogen gas that glow bright red in a long exposure color photograph or CCD image.

But, though an image of Sh 2-235 shows up fairly quickly, 2-231 is much fainter. Indeed, it was necessary for me to do a huge amount of iterative processing, step after step of contrast enhancement, to make the two Sharpless nebulae 2-231 and 2-232 to show up at all in the 1-degree square region of sky I downloaded from the Digital Sky Survey, using the red plate of the POSS2 taken by the Anglo-Australian telescope. Such is the relative brightness of 2-235 that Glen Youman found it necessary only for a series of stacked 5-minute exposures to strongly register it, using a small aperture, fast Takahashi refractor. An even more impressive color image taken by Chris Schur is found here, very clearly depicting the turbulent wave-fronts of layers of excited, expanding hydrogen gas clouds: according to the Sharpless catalogue website entry, "This apparently tiny kidney-shaped HII region is in fact the intersection point of two massive giant molecular clouds (100 thousand and 300 thousand solar masses respectively) with intensive star formation occuring. It is excited by the O9.5 V star BD+35 1201" which, in modern cross-reference, is GSC GSC 2416:541 (10.1 Mv.) And a splendid wide-field monochrome image reveals both Sharpless nebulae, as taken down by the talented James Janusz with his superb AstroPhysics 180 EDF refractor (with field flattener) using an Astrodon H-alpha filter and SBIG ST8-XME imager. Thus, in comparison to the pale image on the original POSS2 red plate, amateurs have now surpassed the best efforts of yesterday's professionals.

There are not many amateur visual sightings recorded on posts found via the Net. I found none in the advanced observers' Yahoo groups "amastro" and "deespskyhunters". Sharpless 2-235 was referenced briefly by Steve Gottlieb, deep-sky maven par excellence who has observed more than 7,000 of the NGC and IC objects, in his very interesting and useful post to the Observers forum mailing list called "Observing with the H-Beta filter," which includes a number of interesting objects that respond well to it, with improved contrast: beyond the usual few items generally discussed. That, and a tidbit here and there in discussions of filters were all that I could find. So my observation will be added to a very small, select group of same.

I found Sharpless 2-235 -- with catalogued size of 10 by 5 arcminutes -- to be the more distinct of the two, though "barely visible" using the UltraBlock filter at low to moderate power in my f/4.7 10" Dob. Sh 2-231 was even paler, "at threshold of detection." I would recommend trying to get an exit pupil of at least 4 millimeters to make the filter work with highest contrast enhancement. And, yes: the H-beta filter did help, but only at the lowest possible power I could employ in my scope with the 1.25" barrel eyepieces I had on hand that could supply an exit pupil no larger than my eye: about 5 mm, which required my 25 mm Orion Ultrascopic eyepiece [48x, 1.1d FOV, 5.3mm exit pupil]: a favored eyepiece I also frequently use when viewing the Horsehead, due to its splendidly efficient light transmission.

But, I can't really claim that the H-beta filter does anything very helpful with Sh 2-231, at least under my conditions and with a 10 inch aperture instrument: it was probably easier to detect its faint "breath" of nebulosity with the UltraBlock. At a catalogued size of 12 by 10 arcminutes, it is exceptionally large and extended, not easily discerned at any but the lowest powers and widest fields; and in my scope, fading out imperceptibly into the background skyglow. The only way I could be sure of it was to move the telescope about a half-degree away, and then back again: the pale haze of the nebula could be seen as a slight change in the sky contrast.

And, sadly, Sh 2-232 (in top picture, above and to the left of Sh 2-235) was, as far as my eyes and scope were concerned, made of the rare element "imaginatium".

Wide Finder Chart: upright, correct

Described as "the closest planetary nebula" (or by some as "one of the closest to the earth"), the Helix nebula is also thus one of the largest- appearing: at an apparent dimension of 14.6 by 12 arcminutes, it is nearly half the diameter of the Moon from our vantage point. Thus, the integrated visual magnitude of a "high" 7.4 can be misleading. The surface brightness of the object is much lower: about 13.2 magnitude per square arcminute of area, not by any means the dimmest planetary, but requiring some effort to see by eye with typical amateur equipment.

In the days before nebular filters, the planetary was considered a dim, challenge object. The original description in the New General Catalogue was "!pF" (meaning 'pretty faint' as it must have looked in the 4 inch aperture telescope of discoverer Karl Harding in 1824.) The central star is a relatively bright 13.4 Mv, which is visible to me at "my site" in either my 10" Dob, or my C-11, with high magnification. But because northern hemisphere observers find that the nebula is low above the horizon, its glory is somewhat diminished.

This image, done by the Canada-France-Hawaii Telescope located in Hawaii, is a much deeper exposure than typical ones that have formed our conception of the object, showing much of the extent of the central nebulosity. When the object is viewed by eye in a telescope of modest size (even as small as 10" aperture) the interior region is significantly gray and opaque; but exposures made on red-sensitive film or with red CCD filters tend to show only the outer helical-shaped gaseous envelope (as in this well-known photo by Dr. David Malin.) This Hubble picture (composited with a ground based view by the 4-meter Blanco Telescope in Chile) illustrates the interior region with a different color rendering. As the "Astronomy Picture of the Day" text explains, "the Helix is not really a simple helix. Rather, it incorporates two nearly perpendicular disks as well as arcs, shocks, and even features not well understood. Even so, many strikingly geometric symmetries remain." According to the wikipedia article, "The nebula is composed of an inner disc with a 8'19" diameter (0.52 pc) and outer torus with a 12'22" diameter (0.77 pc) and an outer-most ring with a 25' diameter (1.76pc). The outer-most ring is flattened on one side due to its colliding with the ambient interstellar medium. The PN is estimated to have been expanding for 6,560 years for the inner disc and 12,100 years for the outer ring... The main ring contains knots of nebulosity which have been detected in many near-by PNs."

The Helix nebula was one of the objects included in our program Eyepiece, in a simulated view with and without a nebular filter. For the image in the program we utilized a color photograph taken by Jim Molinari with a Celestron C-8 scope at prime focus, telecompressed to f/7.5, using Konica 3200 film, and a 20-minute exposure time. The simulation converted the image to monochrome (as the dark adapted eye, using scotopic vision, produces only shades of gray.) The picture on the left is intended to be somewhat similar to the view of the object in a 20 arcminute field, using a 6 to 10 inch aperture telescope without a filter in a light-polluted sky. The right hand picture illustrates the contrast enhancement provided by adding a UHC type (hydrogen line) narrowband nebular filter. Even more enhancement may be provided by an oxygen filter (OIII) at the expense of further reducing the visibility of field stars. Even a gentle slope "LPR" filter will help discern this object. Use large exit pupils, and low power, for best contrast of the nebulosity against the darker sky background. (You will note that the central star is not visible at low powers, which we correctly demonstrate in our simulation.) The excellent image at the top of this discussion was provided by Chuck Vaughn, photographed by him about 20 years ago using a Celestron C-14, telecompressed to f/5.5, using gas-hypered Kodak 2415 monochrome film, and a 60-minute exposure, also contributed to our Eyepiece program: we're pleased to have it, as Chuck has not included some of his oldest astrophotos on his excellent website.

As to the smallest aperture in which the "Helix" will show up to the eye: it is visible as a faint smudge of pale light in the 9x50 finder of the author's 10" Dob, at "the site" in the mountains south of San Jose. In the Minimum Aperture Catalogue page for objects in Aquarius, NGC-7293 is listed as having been seen in 7x35 binoculars. So, the object may be studied with a wide variety of instruments, if the viewer is prepared to expect something pale, large, and barely visible as a dimly glowing "breath" of haze, without definite sharp edges or a well-defined shape. The helical structure is not really discernible as such until one uses a fairly large aperture, aided by a filter -- or in an incredibly dark and transparent sky, preferably at a high elevation. Yet, it has been spotted and studied even in a light polluted suburban area with a telescope of only 3.5 inches aperture: you may read our companion article on Planetary Nebula Observations From Ferguson's List to find out how Donald Ferguson of Houston, Texas, was able to see it with his miniature Questar telescope in one of the brightest city skies in the United States.

I have looked at the Helix nebula so many times over the last three decades that I no longer bother to take any detailed notes. The first time I viewed it at "my site" with my then-new Celestron C-11 GOTO telescope, in early August 2005, I did note my amazement at how bright and clear it was to the eye, near the time it transited, around 3am. Despite being elevated less than 30 degrees above the horizon, the nebula's outer shape and character were immediately recognizable without a filter; aided by both my UltraBlock and O-III filters at the lowest power I typically use on my C-11, under 60x, the view was almost as satisfying as Chuck's photograph, if lacking in the crispness and contrast. A year later I saw it again with the 10" Dob: not quite as distinctly, but (as mentioned above) visible in the finderscope in a sky that at the zenith had few visible naked eye stars fainter than about 5.8 magnitude: the view was not unlike the drawing by Bill Ferris, done at the eyepiece of his 10" Meade telescope. Thus, it is by no means a difficult object at "my site", one that always yields pleasure and satisfaction. However, unlike Mr. Ferguson, I  have never had the pleasure of seeing it from my  yard in San Jose: at best, the object is too low; and the lights from "auto row" a mile away from my home, near Hillsdale Avenue, create a washed out sky that not even an O-III filter can salvage. However, SF bay area light pollution has not deterred Richard Crisp from achieving a spectacular image of the object in H-alpha and OIII wavelengths.

Here's another interesting Arp pair, not difficult and worth investigation by anybody with either a small instrument in very dark, transparent skies, or with (say) an 8" or larger telescope under less excellent viewing conditions. The more northwesterly of the two galaxies, NGC-750, was discovered by William Herschel in 1784 with his 18-inch aperture "speculum" (say, this is getting boring, isn't it?) At least the nearby galaxy of the pair, NGC-751, wasn't:  the Earl of Rosse found it with the "Leviathan of Parsonstown", the world's largest telescope at the time of discovery in 1850.

NGC-750 is the larger and brighter object, its angular diameter being 1.4 by 1.3 arcminutes, with a visual magnitude rating of 12.2 (RNGC states 12.0); NGC-750 is merely 0.9 by 1.3 minutes at 12.5 (again, the RNGC rates it brighter, at 12.2.) In his contributions of modern visual observations to the NGC/IC Project, Steve Gottlieb viewed the pair with both 13 and 17.5" Dobsonians. He states that with the larger telescope, NGC-750 is "moderately bright, small, round. Forms a contact double system with N751 virtually attached at the S end. Resolved into two distinct galaxies at 220x. 13": double galaxy with N751 N-S, two distinct nuclei in a common halo"; with the 17.5" scope, NGC-751 is "Fairly faint, very small, round. Appears smaller and fainter than N750 just off the N edge." In the supplementary index for Arp's Atlas of Peculiar Galaxies, the pair are identified as having "diffuse counter-tails."

A very effective drawing made at the eyepiece of a 10" Newtonian telescope by Wes Stone (whose main web page Sketch Gallery index is here) almost perfectly resembles what I was able to see at "my site" using another 10" telescope, my Orion SkyQuest f/4.7 Dob. On a night with quite superb conditions and at least some reduction of light pollution due to ground fog and a lower elevation temperature inversion, I looked at the Arp pair using several oculars. My logbook for 29 October 2006 indicates that "Arp 166 shows two nuclei < ~1 minute apart, one gx about twice as bright as the other." I used by coincidence quite similar magnification to examine the details of the nuclei that Wes employed for his sketch: my 6mm Expanse eyepiece [200x, 19 min. FOV, 1.3 mm exit pupil], though the galaxies were very clearly apparent in the field with my normal "sweeping" eyepiece, a 21 mm Stratus [57x, 1.2d FOV, 4.4 mm exit pupil].

A slightly higher resolution image of the pair, with clearer separation of the nuclei than the POSS1 blue plate (used by me for the 20-minute wide picture above) may be found on the Arp Galaxies page on the astronomy website of Paul and Liz Downing. who use a C-14 and a Takahashi astrograph for taking digital astro shots from their home in Spain.

I am not even able to locate a single post on a regular public Internet forum of a visual observation of these Van den Bergh bright reflection nebulae (though I suppose they may have occasionally been discussed in one of the "high end" Yahoo astronomy groups for advanced amateurs; and VdB 14 was included as a "challenge" object in a list of 100 items to view in December, by Dave Mitsky.) However, astrophotographers have long made these large, bluish clouds of faint light a target for deep exposures.

The POSS1 sky survey blue plate was used by me to produce an image (at top) that is about a half degree in diameter, though it was cropped offcenter, a few arcminutes to the east, from the download done from VdB 14's coordinates. In this picture, VdB 14 (LBN 682) is a large, irregular near-vertical smear of nebulosity in the region of a very bright star (SAO 24054, 4.2 magnitude.) Unfortunately, the original 48" Oschin Schmidt Palomar plates for this series all suffer from significant "halation" (bleed-through of reflections around the brightest stars), which was a problem of glass photographic plates dating back to the inception of astrophotography. The halation covers up some of the blue reflection glow around the star, connected with VdB 14, and the contrast with the huge bloom of overexposure makes the nebula seem fainter than it should be, in the immediate region of the star.

VdB 15, below, is centered around SAO 24061 (magnitude 4.6) which, again, caused severe halation effects on the original plate. (I should add that the blue plate that showed both these nebulae had many defects, including bright white squiggles -- hairs on the negative, before exposure? -- and long dark scratches, which I did my best to remove with airbrush techniques.)

A modern color CCD image, sensitive to a wider range of frequencies, gives a somewhat different depiction, as seen in this huge, wide digital image covering several degrees, photographed using a 4.9" f/3.8 Wright- Newtonian and Modified Nikon D70 Digital SLR camera in an Austrian dark sky site, by the extremely talented Walter Koprolin. A professional image of the objects, done with the Anglo-Australian 48 inch Schmidt telescope, has an almost mind-boggling brilliance. As one can clearly see, VdB 15 has, in addition to the bluish reflection wavelengths, a reddish hydrogen-alpha component.

For the appearance of the object with more conventional, older film technology, here is a picture done by George Greaney, being a digital composite of two one-hour exposures on hypered 120 format Fuji SHG 400 film, each done on a giant 6x7 negative, using a 6" aperture Astrophysics f/7 EDF Refractor. This particular picture confirms my eyepiece impression, given below; the digital ones have the brightness situation reversed, compared to the way I judged the objects by eye.

On a night that I recorded at "my site" as being "very humid", on 17 November 2006, I used my 10" Orion SkyQuest Dob to view both of these nebulae (which are plotted on Chart 1 of the Tirion Sky Atlas 2000.0.) Unfortunately, without my glasses I have always been so nearsighted that I'm functionally blind and can see clearly only about 4 or 5 inches in front of my eyes (although magnified images in a telescope eyepiece are clear and sharp!) So, I really hate writing observing notes in the dark, and do not much care for using even a red light, which can reflect off white paper and cause a reduction in my dark adaptation. So my notes are almost always briefer than I would desire, later, while studying the objects at the computer. I notated that "VdB 14 & 15 were a general glow around bright stars. 14 is brighter. The SkyGlow filter helps, using either 15 or 9mm Expanses" [Orion wide field oculars: 15 delivers 80x, 50' FOV, 3.2mm exit pupil; 9 provides 133x, 29' FOV, 1.9mm exit pupil].

Incidentally, the SkyGlow filter -- discussed by me in this article -- is a "gentle" general purpose light pollution reduction filter, which has a broad notch covering the frequencies of yellowish light produced by streetlamps; it can also help reduce upper atmospheric skyglow. When used visually, it has a subtle effect that may not always be immediately apparent (especially to beginners, or if the exit pupil used is very large); but with the right magnification, it may almost always help increase the contrast of bluish reflection nebulae. This product is Orion's trade-name for the filter; equivalent ones are marketed by Lumicon ("Deep Sky" filter), Celestron, and other companies (trademarks apply.) Such filters are also very helpful for taking either film or CCD exposures, and will allow longer exposure times before skyfogging occurs (though they do cause a slight color balance shift, which may be corrected by graphics editing software.)

Observers who would like to check their ability to locate and see these objects may acquire finder fields and other information from Mikkel Steine's Deep Sky Browser pages: for VdB 14, and for VdB 15.

"Faint, pretty small, round, gradually brightening toward the middle." That is the decoded abbreviation used in Dr. Dreyer's New General Catalogue of 1888 for this lovely object, known since William Herschel spied it in his 18 inch telescope in 1785. According to the detailed information provided by NED, the galaxy type is a rather complex designation: SAB(rs)bc, which would mean (approximately, as closely as I can figure out, not being an expert) that, according to the de Vaucoleurs extensions, it is a mixed type of spiral, having a small bright elongated nucleus with an intermediate barred condition and interior structure that is partially ringlike. (If you would like to try to do better and come up with the precise description, consult de Vaucoleurs' famous paper on Classification and Morphology.)

The galaxy's catalogued angular diameter is 3.1 by 2.8 arcminutes; its visual magnitude is generally rated at about 11.8; and its surface brightness is 13.9 magnitude per square arcminute, which would mean that it is a somewhat difficult object in small amateur scopes, and not likely to be seen from an urban light-plluted sky. At "my site", on Thursday 23 November 2006, I struggled and suffered in extremely high winds, anxious to be able to get a few objects under my belt before being completely fatigued by the winter conditions at 3,400 feet altitude, near the Pacific ocean. The heavy winds had blown away all traces of ground fog; there was no helpful lower level temperature inversion; and night sky glow was a bit worse than usual -- in fact, much worse than I prefer or experience during optimal nights at this location. But, I marshalled on...

I was employing my 10" Orion scope, having left the GOTO C-11 at home, fearing that the winds would be too much for the instrument to tolerate (since it has a much higher profile than the low-mounted Dob.) In the short focal length of the f/4.7 Newtonian system, the sky glow is even more irritating than usual, driving me to high magnifications whenever practical, to improve contrast. I was not using my computer databases, and only had a copy of the Sky Atlas 2000.0 to guide me; because the conditions had been so very unpropitious for observing, I'd made no plans beforehand, fearing I'd just drive up there, get out into the dreadful wind, and go right home. In fact, I almost did just that!

But, to prove once again that even the least promising occasions sometimes bring delightful surprises, my observation for at least this galaxy -- one of only nine objects viewed before I gave up -- was illustrative, confirming that even under such circumstances, a very careful observer can see details that are not always caught up by others: even if using larger scopes. I am sure, from the number, that I'd seen NGC-255 before; but when? It had not been in the last decade, surely. So my experience with it was almost brand-new; and I had no particular recollections. All I knew about it were the specific details of diameter and magnitude, as well as position: less than half a degree from the magnificent planetary nebula NGC-246 (which I had just finished observing, and report about here.)

Translating my logbook chicken-scratchings into English, I can state that the galaxy was found to be "barely perceived in the 15mm Expanse [80x, 50' FOV, 3.2mm exit pupil], better with the SkyGlow filter. Best with 9mm Expanse [133x, 29' FOV, 1.9mm exit pupil] plus SkyGlow. Elongated slightly (vF)?" I was later so very glad that I had added the last brief remark, in the form of a question. For, when I looked around the Net for information and pictures, I found that -- yes -- the galaxy has extremely faint outer spiral arms that are somewhat more distinct toward the southward direction, especially as shown in this deep color CCD exposure by Adam Block, made with the Kitt Peak visitors' center 20 inch Ritchey. The effect is barely visible on the POSS1 blute plate that I used, above, for the cropped region of about a quarter degree, centered around the galaxy: in fact, I had to enhance the contrast considerably in order to show more than a "bright blob".

This effect may be better shown in a negative mode, but even then many steps of enhancement were necessary, causing the interior details to disappear. I looked on the Net for other amateur astronomers' observations. Yes: Gottlieb had seen the "elongation", which he reported, as seen in his 17.5" Dob, to be 4:3 NNW-SSE, but apparently not detected in his 13 or 8 inch instruments (report available on the pertinent NGC/IC object page, not directly linkable here; or, you may open this text page and search for "NGC-0255" and get the same report by Steve Gottlieb.) The one thing about which I disagree is that I do not find the planetary nebula NGC-246 to be "located 15' SSW" as he says. It seems to me to be further away: in fact, my star chart program tells me it is slightly more than 27 arcminutes away (and the planetary does not show up in the same eyepiece field as a centered NGC-255 when I use my 15 mm ocular, which gives a FOV of 50 arcminutes -- or just under that -- in my 10" Dob: it may be confirmed in the finder chart, below.)

Did anybody else also see the "elongation"? Well, in searching through several pages of Google hits for reports and photos of the object, I didn't find any. For instance, using an 18" F/4.5 Starmaster Dob (which is certainly an excellent instrument!) at Pacheco State Park in northern California (not very far from where I was looking), Bruce Jensen reported only that NGC-255 was "mag. 11.8, small faint round glow with slight central brightening". I also located a few even less informative observations, using smaller scopes and not detecting anything of the central bar (which I could not see clearly, frankly) nor any trace of the elongation. There was an unsigned webpage article about viewing both NGC-246 and NGC-255, by the East Valley Astronomy Club, which said only that, "Not terribly impressive, NGC 255 appears as a bright glow elongated north-south": not really any more explicit than my remarks, but with no telescope aperture cited.

So: how many amateurs have spotted any trace of the elongation, the faint extension of the outward arms? Once again, I must repeat: I had not prejudiced myself by reading a description beforehand, or looking at a picture. My perception was thus not biased. The question that remains unanswered due to the the brevity of the rather cryptic question I added about the galaxy: exactly what had I reported detecting, an extension of the central region of the galaxy, or very much of the southward arm? And how much detail of the inner bar may be perceived, and with what necessary magnification? I shall certainly try to check these details later, in my C-11.

Finally, I was very impressed with the huge, wide angle CCD image of both the planetary and the galaxy on this webpage, taken with a total exposure time of 135 minutes, composited from color and luminance frames, using a Takahashi 140mm astrograph, on the astrophoto website of Ruben Kier (which is irritating to browse, in the extreme, because most pages open up a music file, taken from various commercial rock albums. Get rid of those, Ruben!)

Update: My Finnish deep-sky observing friend Jaakko Saloranta has reported that in his last viewing of NGC-255, it looked ""round with a faint nucleus" but that it is of course very low at his latitude, where even nearby NGC-246 does not look very impressive. He did locate an observation of 255 by one of his acquaintances in the Finnish observing community: the report is not directly linkable but you may get it by going to the Deep Sky Archive and searching for the object. Juha Ojanperä (at Krapisto, Ulvila, Finland) used an 11" SCT at 183x and found that the galaxy was "like a dim and weak glow, that was visible with averted vision only. It was little elongated in W-E direction." His sketch, though, shows none of the very faint arms that I believe I may have barely perceived.

0.5/2 degree finder: upright, correct