Stars Missing

[Orleander]

How long does it take for them to notice stars missing?? Had they seen them before and now they are just 'poof' gone?



A halo of stars surrounding a galaxy in the relatively nearby Virgo cluster is missing, possibly torn away by a neighboring galaxy or snuffed out by the collapse of the cluster itself.

The victim is the giant elliptical galaxy Messier 87, which lives about 50 million light-years away in the center of the Virgo, the closest galaxy cluster to Earth.

"We were surprised to see that the star in the galactic halo in M87 stopped after a certain radius in the center," Ortwin Gerhard, a researcher with Germany's Max Planck Institute for Extraterrestrial Physics, told Discovery News.

Astronomers were looking at planetary nebulae, the exploded remains of stars, using a light-splitting spectrograph at the European Southern Observatory's Very Large Telescope in Chile when they made their discovery.

"It was more like an accident," said Gerhard, co-author of paper scheduled to be published in the journal Astronomy and Astrophysics. "We were studying the Virgo cluster trying to find stars that do not belong to galaxies, but lie between them."

http://dsc.discovery.com/news/2009/06/08/galaxy-messier-star.html

[cosmictraveler]

How long does it take for them to notice stars missing?? Had they seen them before and now they are just 'poof' gone?

Seeing that there are trillions of stars out there it would seem very difficult to find the ones that just fade away from time to time. Just keeping track of the billions of stars in our own galaxy is hard enough.

[Orleander]

I can see that with one star but several in the same area?

[cosmictraveler]

I can see that with one star but several in the same area?

Again with only a few astronomers viewing different things, not many are counting the stars every night. To many other things happening I would think than to worry about a few "missing" stars. There's only so many telescopes and so much time to do investigating as they say. :)

[Orleander]

but stars don't vanish in a few days, months or even years.

[cosmictraveler]

but stars don't vanish in a few days, months or even years.

Yes they do, when they just fade away there's little light left to see any longer. Like a candle when you blow it out and the wick has a little red glow that is barely seen.

[D H]

How long does it take for them to notice stars missing?? Had they seen them before and now they are just 'poof' gone?

Whoa there! You misinterpreted the article, Orly. (That the article is poorly written doesn't help.) The stars are not missing in they were their yesterday and today they are gone. The stars are missing only in the sense that astronomers' models of how galaxies form and evolve say stars should be there. Well, the stars aren't there. That doesn't necessarily mean they disappeared. It might just mean that the stars were never there -- and that the models need some tweaking.

Aa better written lay article about the same topic:
http://www.sciencedaily.com/releases/2009/05/090520114716.htm

[nietzschefan]

They guess on the locations of some object, they cannot see based on the movement, etc of nearby objects. They are wrong all the time.

[grimace]

i have to agree with whtas been said. i think that if stars disappeared that quickly there would be far fewer. two thumbs down and holding my nose on this one.

[phlogistician]

On stars going 'poof' though, they are noticed very quickly, a worldwide network of telescopes watches the sky 24/7 and detects supernovae as they happen, and then gets many other telescopes to monitor the event, at various wavelengths, for some time after.

[Orleander]

Whoa there! You misinterpreted the article, Orly. (That the article is poorly written doesn't help.) The stars are not missing in they were their yesterday and today they are gone. The stars are missing only in the sense that astronomers' models of how galaxies form and evolve say stars should be there. Well, the stars aren't there. That doesn't necessarily mean they disappeared. It might just mean that the stars were never there -- and that the models need some tweaking.

Aa better written lay article about the same topic:
http://www.sciencedaily.com/releases/2009/05/090520114716.htm

oooooohhhh, I get it. :o
You're right, it is poorly written, because it says a halo of stars is missing, and then gave the reasons why.
Thanks DH