Russell Croman Astrophotography  



The Swan Nebula
in Elemental Colors

About This Photograph

The Swan Nebula is a star-forming region in the Milky Way, in the constellation of Sagittarius. In this image, special filters were used to isolate only the light of certain elements, which glow under the illumination of newborn stars within the nebula. Red, green and blue channels were assigned to Sulphur-II, Hydrogen-alpha and Oxygen-III emission lines, respectively.

The gas is also being forced away from the stars and running into other clouds of dust and gas in surrounding space. This causes the numerous mountainous-looking ridges, known as ionization fronts, seen throughout the image.


Technical Details

Optics:14" f/10 RCOS Ritchey-Chr├ętien Cassegrain at f/10.
Camera:SBIG ST-10XME, CFW8.
Mount:Takahashi NJP Temma 2.
Filters:Custom Scientific 3nm Sulphur-II, H-alpha, Oxygen-III.
Dates/Times:16-17 May, 21, 29 June.
Location:my backyard observatory in Austin, Texas.
Exposure Details:SII:Ha:OIII = 120:140:180 minutes (20-minute sub-exposures).


Publication Data for this Photograph

Date Publication Type
2003-08-11 NASA's Astronomy Picture of the Day Web Site