Coalsack Dark Nebula (Caldwell 99)
The Coalsack Nebula or Caldwell 99 is the most prominent dark nebula in the sky, easily visible to the naked eye as a dark patch silhouetted against the southern Milky Way.Located in the constellation Crux, it has an angular diameter is 400x300 arc-minutes and lies at an estimated distance of 610 light years. The Equinox 2000 coordinates are 12h 53.0m, -63° 00´ which makes the Coalsack a Southern Hemisphere object that is best seen during the spring. The Caldwell Spring Star Chart shows the position of all Caldwell objects visible during that season. Visit the Caldwell Catalog Photo Gallery to see more objects from this catalog.
See Wikipedia for more details.
Technical Details
- Object: Coalsack Dark Nebula
- Other Names: Caldwell 99
- Object Type: dark nebula
- Object Data: Angular Size = 400x300 arc-minutes
- Object Position (Equinox 2000): 12h 53.0m, -63° 00´, Constellation = Crux
- Date/Time: 2011 May 30 at 01:53 UTC
- Location: Hotel Inca Utama, Huatajata, Lake Titicaca, BOLIVIA
- Mount: Celestron CG-5 GT
- Lens: Nikkor AI 105mm f/2.5
- Camera: Canon EOS 550D (Rebel T2i)
- Field of View: 12.1° x 8.1° at 8.4 arc-sec/pixel (web version: 47.2 arc-sec/pixel)
- Exposure: 2 x 240s, f/2.8, IE800
- File Name: SS105-19_20w.jpg
- Processing (Adobe Camera Raw): Vignetting Correction, Noise Reduction, White Balance, Curves
- Processing (Photoshop CS5): Average Images, Curves
- Original Image Size: 3454 × 5179 pixels (17.9 MP); 11.5" x 17.3" @ 300 dpi
- Rights: Copyright 2012 by Fred Espenak. All Rights Reserved. See: Image Licensing.