In a star's final days, astronomers hunt 'signal of impending doom'

Nov 30, 2011 by Pam Frost Gorder
This Large Binocular Telescope image below of the Whirlpool Galaxy, otherwise known as M51, is part of a new galaxy survey by Ohio State University, where astronomers are searching for signs that stars are about to go supernova. The insets show one particular binary star system before (left) and after (right) one of its stars went supernova. Credit: Image by Dorota Szczygiel, courtesy of Ohio State University.

(PhysOrg.com) -- An otherwise nondescript binary star system in the Whirlpool Galaxy has brought astronomers tantalizingly close to their goal of observing a star just before it goes supernova.

The study, submitted in a paper to the , provides the latest result from an Ohio State University underway with the Large Binocular Telescope, located in Arizona.

In the first survey of its kind, the researchers have been scanning 25 for stars that brighten and dim in unusual ways, in order to catch a few that are about to meet their end. In the three years since the study began, this particular unnamed binary system in the was the first among the stars they've cataloged to produce a supernova.

The astronomers were trying to find out if there are patterns of brightening or dimming that herald the end of a star's life. Instead, they saw one star in this dim noticeably before the other one exploded in a supernova during the summer of 2011.

Though they're still sorting through the data, it's likely that they didn't get any direct observations of the star that exploded – only its much brighter partner.

Yet, principal investigator Christopher Kochanek, professor of astronomy at Ohio State and the Ohio Eminent Scholar in Observational Cosmology, does not regard this first result as a disappointment. Rather, it's a proof of concept.

"Our underlying goal is to look for any kind of signature behavior that will enable us to identify stars before they explode," he said. "It's a speculative goal at this point, but at least now we know that it's possible."

"Maybe stars give off a clear signal of impending doom, maybe they don't," said study co-author Krzystof Stanek, professor of astronomy at Ohio State, "But we'll learn something new about dying stars no matter the outcome."

Postdoctoral researcher Dorota Szczygiel, who led the study of this supernova, explained why the galaxy survey is important.

"The odds are extremely low that we would just happen to be observing a star for several years before it went supernova. We would have to be extremely lucky," she said.

"With this galaxy survey, we're making our own luck. We're studying all the variable in 25 galaxies, so that when one of them happens go supernova, we've already compiled data on it." The supernova, labeled 2011dh, was first detected on May 31 and is still visible in telescopes. It originated from a in the Whirlpool Galaxy – also known as M51, one of the galaxies that the Ohio State astronomers have been observing for three years.

The system is believed to have contained one very bright blue star and one even brighter red star. From what the astronomers can tell, it's likely that the red star is the one that dimmed over the three years, before the blue star initiated the supernova.

When the Ohio State researchers reviewed the data as well as Hubble Space Telescope images of M51, they saw that the red star had dimmed by about 10 percent over three years, at a pace of three percent per year.

Szczygiel believes that the red star likely survived its partner's supernova.

"After the light from the explosion fades away, we should be able to see the companion that did not explode," she said.

As astronomers gather data from more supernovae – Kochanek speculates that as many as one per year could emerge from their data set – they could assemble a kind of litmus test to predict whether a particular star is near death. Whether it's going to spawn a supernova or shrink into a black hole, there may be particular signals visible on the surface, and this study has shown that those signals are detectable.

The team won't be watching our sun for any changes, however. At less than 10 percent of the mass of the star in supernova 2011dh, our star will most likely meet a very boring end.

"There'll be no for our sun – it'll just fizzle out," Kochanek said. "But that's okay – you don't want to live around an exciting star."

Explore further: Using supermassive black holes to measure cosmic distances

More information: iopscience.iop.org/0004-637X

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User comments : 8

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omatumr
1.3 / 5 (15) Nov 30, 2011
In a star's final days, astronomers hunt 'signal of impending doom'


If the explosion is caused by neutron repulsion [1] in the stellar core, there may be no 'signal of impending doom' in the glowing sphere of waste products (H and He) that has accumulated high above the neutron core.

"Neutron Repulsion", The
APEIRON Journal, in press, 19 pages (2011);
http://arxiv.org/...2.1499v1

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo
Video Summary (1961-2011)
http://dl.dropbox...reer.pdf
bewertow
4.6 / 5 (11) Nov 30, 2011
lol wtf are you talking about. Do you know anything about astrophysics?
Silverhill
4.6 / 5 (11) Nov 30, 2011
It would not seem so. He thinks, for instance, that a neutron star would be stable even with a mass of only 70% of the Chandrasekhar limit.
jsdarkdestruction
3.5 / 5 (8) Dec 01, 2011
Oliver Manuel's recent efforts to plaster Physorg.com and other public news sites with his theories and personal URLs are a bit puzzling, as scientists have a variety of publications available to communicate directly to each other in. My best guess is that he is desperately trying to prop up his legacy in light of his arrest in his university office on 7 charges of rape and sodomy based on allegations by 4 of his own children. The charges have been reduced to one count of felony attempted sodomy, not necessarily because of his innocence, but because of the statute of limitations. One can only guess how the recent charges and decades of family strife have affected his ability to reason rationally and to remain objective while defending his unpopular theories.

http://www.homefa...uel.html

http://mominer.ms...hildren/
FrankHerbert
1.1 / 5 (54) Dec 01, 2011
I saw the two votes against jsdarkdestruction, and thought, now just who other than Oliver would do that?

Parsec also voted it 1.

Parsec, Member since: September 24, 2007, 11:58 am
omatumr, Member since: September 24, 2007, 11:57 am

Well that was easy. LOL
MarkyMark
5 / 5 (3) Dec 01, 2011
lol wtf are you talking about. Do you know anything about astrophysics?

Lets just say that omapaedo doesant. After all he religiously believes that ower sun is a Neutron star. And he constantly tries to link pretty much any article with his theory even when it has nothing to do with Astrophsics.
omatumr
1 / 5 (3) Dec 03, 2011
Astrophysicists may be interested in this report from Amsterdam on another manifestation of the enormous potential energy (mass) stored in neutron stars:

"Fastest spinning star ever discovered"

www.nu.nl/wetensc...ekt.html

It includes this intriguing quote about a star close to us:

"The equatorial rotational velocity of 102 VFTS is three hundred times greater than that of the sun, and thus approaching the point where centrifugal forces would tear the star apart."

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo
http://myprofile....anuelo09
barakn
not rated yet Dec 03, 2011
I saw the two votes against jsdarkdestruction, and thought, now just who other than Oliver would do that?

Parsec also voted it 1.

Parsec, Member since: September 24, 2007, 11:58 am
omatumr, Member since: September 24, 2007, 11:57 am

Well that was easy. LOL

Not nearly as easy as you think. Physorg existed prior to Sept. 24, 2007 but did not have user accounts, as it was formally linked to physforum.com, which was becoming a cesspool of vitriol and spam. Physorg already had a number of frequent visitors when it decided to introduce user accounts, and there was a rush of users to claim their accounts the instant this feature was turned on. Let's see if you think any of these users are omatumr sockpuppets:
aennen September 24, 2007, 11:56 am
gmurphy September 24, 2007, 11:58 am
A_Paradox September 24, 2007, 11:58 am
Valentiinro September 24, 2007, 11:58 am
mikiwud September 24, 2007, 11:58 am
pinkelephant September 24, 2007, 11:58 am
zephir September 24, 2007, 11:56 am

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