Astronomical Picture of the Day, APOD November 23, 2007
The official designation for this planetary nebula is PK205+14.1. It is also listed as Abell 21 and Sharpless 274. It is a very large PN in Gemini perhaps 10 arcmin in diameter. The brighter portion pointing to the SE gives it a crescent moon appearance, but closer inspection shows fainter regions toward the NW. Thus, it probaby has an ellipsoidal shape. North is to the lower left.
This image is comprised of 6 nm H-a mapped to red and 3 nm OIII mapped to equal mixtures of green and blue to enhance contrast and bring out the incredible structure within the PN. Star colors were blended in from G2V-balanced RGB data.
Description
Exposure: 2 hrs H-a, OIII, 9 min each R,G,B
Telescope: RCOS 16" RC f/8.9 tube
Mount: Software Bisque Paramount ME
Oag: Astrodon MonsterMOAG
Acquisition: CCD AutoPilot3
Calibration: CCDStack
Observatory Site: Sierra-Remote Observatories, Shaver Lake, CA
Telescope: RCOS 16" RC f/8.9 tube
Mount: Software Bisque Paramount ME
Oag: Astrodon MonsterMOAG
Acquisition: CCD AutoPilot3
Calibration: CCDStack
Observatory Site: Sierra-Remote Observatories, Shaver Lake, CA
Camera: SBIG STL11000
Filters: Astrodon 6 nm H-a, OIII Gen 1 RGB
Guider: SBIG ST-402
Camera Operation: MaximDL4.62
Processing: Photoshop CS2
Image Date: 11/12/2007
Filters: Astrodon 6 nm H-a, OIII Gen 1 RGB
Guider: SBIG ST-402
Camera Operation: MaximDL4.62
Processing: Photoshop CS2
Image Date: 11/12/2007