Russell Croman Astrophotography  



IC 1396
in Elemental Colors

About This Photograph

IC 1396 is cataloged as a star cluster with associated nebulosity. In this image, special filters were used to isolate the light of energized sulphur, hydrogen, and oxygen atoms.

From just below center to the bottom of the image is the intriguing Elephant's Trunk nebula. It is a dark globule of gas and dust being eroded by the radiation pressure from the bright stars above it. Numerous other such globules of varying size are scattered throughout the nebula. Some of these are positioned between us and the bright clouds of gas, and so appear as inky black silhouettes.

With the filters and color scheme used in this image, color is indicative of energy in the nebula. Blue represents oxygen, which takes the most energy to excite. Next easiest to excite is hydrogen, which is represented by green. Sulphur, color coded red, is the easiest element of the three to ionize. From the resulting color patterns, one can see the influence of the bright stars at the center of the nebula, which are the sources of ultraviolet radiation that power it.


Technical Details

Optics:Takahashi FSQ-106N.
Mount:Astro-Physics AP1200GTO.
Filters:Custom Scientific 5nm H-alpha, S-II, and O-III.
Dates/Times:17 August 2004.
Location:my backyard observatory in Austin, Texas.
Exposure Details:SII:Ha:OIII = 2:4.5:1.75 hours (15-minute individual exposures).


Publication Data for this Photograph

Date Publication Type
Image of the Day
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