Object Information:                M20 (NGC 6514)  "Trifid Nebula"
                                              Mag. -   6.3
                                              Constellation - Sagittarius
                                              Location -  R.A. 18:02.3,  Dec. -23.02
                                              Size - 30 light years across,
                                              Distance -  6.700 light years [Kepple & Sanner, Night Sky Observers Guide],

General Noted:  This combination emission and reflection nebula is a showpiece of the summer Milky Way.  M20 can be easily spotted as a patch of nebulosity and stars with binoculars.  The dust lanes which inspired its name are visible with medium size amateur telescopes of 8 to 10 inch aperture.

M20, also known as the Trifid Nebula, was first observed by Le Gentil in 1747 and was subsequently "rediscovered" by Messier in June 1764.  Burnhams Celestial Handbook reports that John Herschel was probably the first to call M20 the Trifid Nebula and described it as "consisting of 3 bright and irregularly formed nebulous masses..."

M20 is made up of two separate components, the lower half which contains the conspicuous dust lanes is an emission nebula which glows with the characteristic pink of H II emissions.  The less conspicuous upper half is a blue colored reflection nebula which reflects the light from the bright central star.

Imaged at:                              Organ Pipe Cactus National Monument, Arizona
                                              Elevation - 2,500 feet

Equipment:                             Optics - Takahashi MT-160 at f/6.1
                                              Mount - Astro-Physics 900 GTO,
                                              Camera - Santa Barbara Instrument Group (SBIG) ST-7E NABG CCD,

Exposure Information:            May 7, 2003
                                             Luminance - Sum of 34 sixty second individual exposures, R-300 sec., G-300 sec., B-480 sec.  

Image Acquisition Software:   CCDSoft,

Image Processing Software:    Image calibration with AIP for Windows, Image registration and stacking with MIRA AP 6 and Registar, LRGB processing with Photoshop 7.