by Ann » Thu Sep 13, 2012 4:59 am
What a great image!
I love the protrait of the nebulosity in this area. I have never before seen that ridge of red Ha emission directly behind the Cocoon, with the Cocoon sort of "sticking out of it". This structure makes the Cocoon very slightly similar to the
Horsehead region. There, too, you have a conspicuous feature sticking out across a red ridge of nebulosity. And the prominent blue reflection nebula "below" the Horsehead is slightly similar to the Cocoon Nebula itself.
Note the long dusty filament which is light brown in color near the Cocoon, but becomes dark, almost pitch black, away from it. The Cocoon has formed at the end of this long string of dust. Fascinatingly, dust clouds often seem to be really quite elongated.
Here is an example of an elongated star forming dust cloud in Corona Australis.
I don't have my software here - darn it! - so I can't check the central star of the Cocoon, but I have looked it up before. I know that this star has been classified as a relatively unremarkable star of cool class B, but that must be a misclassification. I don't see how this star could fill the Cocoon with red light if it wasn't at least of early class B, spectral class B2 or earlier.
Once again, this is a spectacular APOD!
Ann
What a great image! :D :D :D
I love the protrait of the nebulosity in this area. I have never before seen that ridge of red Ha emission directly behind the Cocoon, with the Cocoon sort of "sticking out of it". This structure makes the Cocoon very slightly similar to the [url=http://www.nasa.gov/images/content/52238main_MM_image_feature_89_jw4.jpg]Horsehead region[/url]. There, too, you have a conspicuous feature sticking out across a red ridge of nebulosity. And the prominent blue reflection nebula "below" the Horsehead is slightly similar to the Cocoon Nebula itself.
Note the long dusty filament which is light brown in color near the Cocoon, but becomes dark, almost pitch black, away from it. The Cocoon has formed at the end of this long string of dust. Fascinatingly, dust clouds often seem to be really quite elongated. [url=http://www.vindianz.com/wp-content/uploads/2009/12/Stars-and-Dust-Across-Corona-Australis-5-June.jpg]Here[/url] is an example of an elongated star forming dust cloud in Corona Australis.
I don't have my software here - darn it! - so I can't check the central star of the Cocoon, but I have looked it up before. I know that this star has been classified as a relatively unremarkable star of cool class B, but that must be a misclassification. I don't see how this star could fill the Cocoon with red light if it wasn't at least of early class B, spectral class B2 or earlier.
Once again, this is a spectacular APOD! :D
Ann