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antoniseb
2005-Sep-20, 05:28 PM
Here's a New Scientist article about a ring of about 400 young blue stars in a roughly one light year diameter ring around the central SMBH in M31.

http://www.newscientistspace.com/article.ns?id=dn8025

The article says they are surrounded by a larger elliptical ring of older read stars about 5 lightyears in across.

At the moment there is no certainty as to how these stars formed, but it seems likely that the formation of such rings around SMBHs is probably a normal phenomenon.

IMO
2005-Sep-20, 05:51 PM
Here's a New Scientist article about a ring of about 400 young blue stars in a roughly one light year diameter ring around the central SMBH in M31.

http://www.newscientistspace.com/article.ns?id=dn8025

The article says they are surrounded by a larger elliptical ring of older read stars about 5 lightyears in across.

At the moment there is no certainty as to how these stars formed, but it seems likely that the formation of such rings around SMBHs is probably a normal phenomenon.

Here is the NASA release on this
http://hubblesite.org/newscenter/newsdesk/archive/releases/2005/26/

Does this suggest that the "star rings" of Schmidt-Kaler and Isserstedt were real :) ?
http://weblore.com/richard/stellar_rings.htm

By about 1970 most astronomers had concluded that they were accidental asterisms.

Fraser
2005-Sep-20, 07:06 PM
SUMMARY: Astronomers have known about a strange blue light coming from the heart of the Andromeda Galaxy (M31) for many years, but they were never sure exactly what it was. Thanks to new observations from Hubble, they now know it's a ring of young hot stars which are whipping around the supermassive black hole in the middle of M31. The 400 stars are packed into a disk only 1 light-year across, which is nestled inside a larger ring of older, redder stars. Our own Milky Way might have a similar phenomenon, which means this could be the situation in most galaxies.

View full article (http://www.universetoday.com/am/publish/blue_halo_stars_blackhole.html)
What do you think about this story? post your comments below.

AndyHolland
2005-Sep-20, 08:30 PM
It would be interesting if they did a detailed spectral analysis for hydrogen and helium.

The core of a star is tightly packed, and it takes a bit of time for light to thermalize and migrate to the surface (a million years in the case of our own sun). If there are allot of gravity induced pressure waves, there may be numerous "cracks" in the thick plasma (far denser than lead) that allow for more surface heating, and this blue shifts the starlight at the surface that is observed.

One could probably tell readily based on helium and hydrogen absorption lines. Also one could compare X-Ray emissions from the stars to those of other regular blue stars to see if there is a difference.

andy

antoniseb
2005-Sep-20, 08:46 PM
If there are allot of gravity induced pressure waves, there may be numerous "cracks" in the thick plasma (far denser than lead) that allow for more surface heating, and this blue shifts the starlight at the surface that is observed.

I'm not sure what you mean by "cracks" in this case. Are you talking about convection coming up from the core of these stars?

Also what is it you are hoping to see by this analysis (which is beyond the capability of current instruments)? Do you hope to see the element abundances in these stars to see if they are different from normal?

I saw an article several months ago suggesting that the blue star near our SMBH were possibly the cores of old red giants that had had their outer envelopes stripped away. Maybe that's the same thing we're seeing here.

Launch window
2005-Sep-20, 10:35 PM
very odd

so maybe we'll start finding this strange blue light in places other than Andromeda's core - 2.2 million miles an hour is a good speed

it is very strange activity and perhaps our own Milky Way apparently has much of the same going on

Greg
2005-Sep-21, 03:23 AM
http://www.universetoday.com/am/publish/fountain_youth_core.html?1242005

Above is a link to an article that may help explain this phenomenon. Basically it states that These stars could have migrated inward from more distant clusters and in so doing have had mass stripped off, making them look younger and bluer that they should. Call it a chemical peel for a star.

The fact that massive stars can form from the accretion disc itself is not news. Here is a link to an article asserting this.

http://arxiv.org/abs/astro-ph/0307084

AndyHolland
2005-Sep-21, 02:13 PM
I think the stripping of the outer layer of gases is far more likely. The article seems to insist these are young stars, so maybe there are details indicating this that are not provided.

What I meant was less thermalized light heating outer gases because there are perhaps transient pathways in which harder photons (x-rays too?) can escape caused by pressure waves. So that is a hypothetical radiative process as opposed to convective process. The density is so incredibly high in a star's interior the term crack seemed more appropriate.

bigsplit
2005-Sep-21, 03:20 PM
it is a situation where old stars were not striped, but the tidal forces completely destroy the stars generating clouds of elements. The heavier elements are removed from the cloud by g and new stars are being formed with the lighter elements.

Just a guess.