APOD: Cocoon Nebula Deep Field (2018 Sep 19)

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APOD Robot
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APOD: Cocoon Nebula Deep Field (2018 Sep 19)

Post by APOD Robot » Wed Sep 19, 2018 4:05 am

Image Cocoon Nebula Deep Field

Explanation: Inside the Cocoon Nebula is a newly developing cluster of stars. The cosmic Cocoon on the upper right also punctuates a long trail of obscuring interstellar dust clouds to its left. Cataloged as IC 5146, the beautiful nebula is nearly 15 light-years wide, located some 3,300 light years away toward the northern constellation of the Swan (Cygnus). Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by young, hot stars and blue, dust-reflected starlight at the edge of a nearly invisible molecular cloud. In fact, the bright star near the center of this nebula is likely only a few hundred thousand years old, powering the nebular glow as it slowly clears out a cavity in the molecular cloud's star forming dust and gas. This exceptionally deep color view of the Cocoon Nebula traces tantalizing features within and surrounding the dusty stellar nursery.

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Ann
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Re: APOD: Cocoon Nebula Deep Field (2018 Sep 19)

Post by Ann » Wed Sep 19, 2018 5:00 am

The Cocoon Nebula. Photo: Fabian Neyer.
The Trifid Nebula. Photo: Kfir Simon.


















The Cocoon Nebula bears a striking resemblance to the Trifid Nebula. The Cocoon appears to be a little smaller, 15 light-years across according to today's caption, versus 21 light-years across for the Trifid.

For what it's worth, I'm pretty sure that the central star of the Cocoon is the only really massive star that has formed there so far. All the other stars that can be seen inside the Cocoon seem to be a lot more modest and lightweight. I think that the Trifid is a bit more well-endowed.

Another difference is that the central star of the Trifid Nebula is an O7.5III star, whereas the central star of the Cocoon belongs to spectral class B1. It is therefore not as hot as the power engine of the Trifid, and also not as massive. According to Wikipedia, the mass of the central star of the Trifid is around 20 M, while the mass of the Cocoon luminary is around 14 M.

Another similarity between the Cocoon and the Trifid is that both these nebulas are very young.

Ann
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Re: APOD: Cocoon Nebula Deep Field (2018 Sep 19)

Post by Boomer12k » Thu Sep 20, 2018 12:46 am

Ann wrote:
Wed Sep 19, 2018 5:00 am
The Cocoon Nebula. Photo: Fabian Neyer.
The Trifid Nebula. Photo: Kfir Simon.


















The Cocoon Nebula bears a striking resemblance to the Trifid Nebula. The Cocoon appears to be a little smaller, 15 light-years across according to today's caption, versus 21 light-years across for the Trifid.

For what it's worth, I'm pretty sure that the central star of the Cocoon is the only really massive star that has formed there so far. All the other stars that can be seen inside the Cocoon seem to be a lot more modest and lightweight. I think that the Trifid is a bit more well-endowed.

Another difference is that the central star of the Trifid Nebula is an O7.5III star, whereas the central star of the Cocoon belongs to spectral class B1. It is therefore not as hot as the power engine of the Trifid, and also not as massive. According to Wikipedia, the mass of the central star of the Trifid is around 20 M, while the mass of the Cocoon luminary is around 14 M.

Another similarity between the Cocoon and the Trifid is that both these nebulas are very young.

Ann
So I wasn't the only one to notice the similarity between them...

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