Gamma Ray Burst

Cackmobile writes "The Sydney Morning Herald is reporting that some Australian scientists have been watching a gamma-ray burst. The article makes some good points about the origins of these." Update: 03/21 03:27 GMT by T : MickDownUnder writes with a link to NASA's press-releasy version, with story, pictures and animations.

What is the news??

[Frans Faase]

The article does not say much, except that a long observation of a gamma burst was made. In the conclusion it says: "Mr Price said astronomers were not sure what caused gamma-ray bursts."

Re:What is the news??

[Ashtray_Waterloo]

It's the birth of a black whole. Have a cigar!

Here's a link to an article on Yahoo!News:

LINK [yahoo.com]

SWIFT

[little1973]

Nasa is building a satellite capable of catching gamma-ray burst on the fly. Here's the link. [nasa.gov]

Not much here

[bzcpcfj]

From the article: "They could be the birth cry of black holes formed from the ruins of a supernova or the result of colliding black holes or neutron stars." Those are hardly new theories. The article doesn't say how the observers happened to catch the burst as it happened, what observers were able to see in the "weeks" (which is a long time for a gamma ray burst) that followed, or what the artist's conception of a Wolf-Rayet star has to do with any of this. On the whole, a very disappointing article. This story [nasa.gov], published last October 8 by NASA is much more informative.

Weeks is appropriate

[barakn]

what observers were able to see in the "weeks" (which is a long time for a gamma ray burst)

The gamma rays themselves persist anywhere from .01 to 1000 s. Even with HETE-2, we have almost no chance of pinpointing the location of the short GRBs. But the long ones last long enough to pinpoint their location with X-ray telescopes. If that happens, then the GRB can be observed across the energy spectrum from X-rays to radio waves. They often take weeks before they dim to the point they can't be distinguished from their host galaxies. The misperception that gamma rays bursts are fleeting comes from the days before the BeppoSAX satellite launch in 1996, when positions could not be located precisely enough for follow up observations in other regions of the spectrum.

Long GRBs (such as the one lst October) are probably caused by hypernovae or collapsars, where a massive star (at least 20x our sun's mass, not the 10-15 solar mass star mentioned in the Sydney Morning Herald) has its core collapse into a black hole, perhaps after collapsing into an intermediate neutron star. The short GRBs are probably the result of mergers between massive compact objects like white dwarfs, neutron stars, and black holes.

Re:Weeks is appropriate

[ggwood]

I think the conventional 0.01s to 1000s figures are how long they last in gamma rays. Do the bursts last longer in other forms of light?

Also, does anyone know what the Wolf-Rayet star has to do with anything? Is it a possible burst candidate? I read the origional article and the gsfs.nasa.gov link and I didn't find any mention of this.

Does the "Wolf-Rayec" star classification refer to a massive star about to collapse?

All Astronomy Picture of the Day ( here [nasa.gov]) says about it is that Wolf-Rayec stars are a

Re:Weeks is appropriate

[barakn]

I think the conventional 0.01s to 1000s figures are how long they last in gamma rays. Do the bursts last longer in other forms of light?

That was exactly the point in my last post. When the gamma rays are gone the show isn't over.

From this one might assume Wolf-Rayet stars might already have undergone an event which might have caused a GRB (gamma ray burst)?

No. These massive stars have (usually) burned through most of their supply of hydrogen and are furiously burning helum. They are losing their outer

Re:Not much here

[golo]

Coincidentally yesterday NASA came out with this article [nasa.gov] about the October event. HETE [mit.edu] satellite catched a gamma-ray burst "[it] spotted the burst, nailed down a location, and notified observers worldwide within a few seconds, while the gamma rays were still pouring in". It turns out that there is a "Gamma-ray burst Coordinates Network [nasa.gov]", and an Automated Telescope in Japan that started observing just 193 after the burst was detected. cool story.

Gamma Ray Bursts

[John Sullivan]

"They've been described as the biggest bang since the big [bang]."

I thought that was Zaphod Beeblebrox?

HULK Smash!!!

[docbrown42]

Run for your lives! There are scattered reports of the scientists turning into gigantic, green, muscle-bound monsters after beein exposed to the Gamma Ray Burst. Run! Hide! Flee!

Re:HULK Smash!!!

[ggwood]

Run for your lives! There are scattered reports of the scientists turning into gigantic, green, muscle-bound monsters after beein exposed to the Gamma Ray Burst. Run! Hide! Flee!



Ya that was just moments after said scientists decoded the secret message encoded in the burst which began: "All your base are..."

If I was a sentient life form...

[Dread_ed]

What better way to get the attention of another sentient species than by creating massive gamma ray bursts that could be seen the all over the universe!

Maybe SETI needs to take a closer look at these bursts?

Re:If I was a sentient life form...

[ktulu1115]

Maybe SETI needs to take a closer look at these bursts?

Only small problem with that is the Arecibo Telescope is designed to receive radio waves... a far cry away from gamma rays in the electromagnetic spectrum.

Re:If I was a sentient life form...

[Dread_ed]

Any life form sufficiently advanced enough to create one of these bursts would probably know not to stand next to it when it went off.

Hmmmm, they might even be able to shield against it! Ooooh! Technology!

Australian Scientists....

[WanChan]

You wouldnt like them when theyre angry.

Science Daily

[Alizarin Erythrosin]

Science Daily has an article [sciencedaily.com] about it too, saying "Scientists arriving on the scene of a gamma-ray burst just moments after the explosion, have witnessed the death of a gigantic star and the birth of something monstrous in its place, quite possibly a brand new, spinning black hole."

This is exciting, seems like we have a first hand look at the formation of a black hole!