Gamma Ray burst in the Milkey Way

talmans

If the exploding star that caused the gamma ray burst on Wednesday had occurred as close to us as Alpha Centauri what would be the effect on Earth?

turbo

Depends on proximity. If on the far side of the MW, we'd probably get a really good dose of extra UV and higher-energy radiation. If in our stellar neighborhood, goodbye terrestrial life on Earth, though the oceans could protect enough organisms to allow for the re-emergence of life.

DaveC426913

He did specify proximity: Alpha Centauri - 4ly.

We don't what what the objects are that cause these bursts. But considering the light reached halfway across all of creation, I'm sayin' whatever emitted it might easily be 4ly in diameter. And even if not, the expansing ball of radiation could conceivably turn the Solar System into atomic vapour, if not plasma. But it's just guesswork.

DaveC426913

One could consider that, what with all the speculation of life distributed throughout the universe, there's likely now a big, dead wasteland out there, untold light years in radius.

We are now a little bit more alone.

Saladsamurai

Thanks Dave. As depressed as I was before I logged on tonight you have somehow managed to worsen it.

Laura1013

Chin up, Casey. Life is resilient. There's some speculation that a GRB caused Earth's Ordovician extinction, but not all life on Earth was destroyed.

To answer the original question:

They cite The History Channel, so I'm not sure how this calculation was done, but there you go.

talmans

mmm. no chance we all become super heros

talmans

Ligo didn't report any news on a gravity wave. i think the burst was too far away to detect a wave.

my_wan

This GRB was 7.5 billion light years away making it that far in the past. Our solar system is only about 4.5 billion years old. Even if life got caught in the blast it would be unlikely to have any meaning to neighbors we can expect today. How many star births can be attributed to an event that size? If a technological civilization has actually been around that long their civilization would be unimaginable to us. GRBs may however be why we appear to be alone at present.

I wonder how difficult it would be to hide from such a blast if we were a non-terrestrial race living on small semi-mobile artificial worlds. Could we even predict the timing of such an occurrence nearby? How effective would hiding behind a star be? Shielding would be limited and scattering would reduce effectiveness but perhaps make it survivable.

xCross

Star half way across the known universe exploded when existence was half its current age

There is an old adage that goes, “If a tree falls in a forest and no one is around to hear it, does it make a sound?"

A similar question was answered on Friday, “If a star blew up some 6 billion years ago when no one was on Earth, would anyone have seen it?”

The answer to that question is yes, we could see it, last week in fact. A star in a distant, previously unknown galaxy, exploded when the universe was about half its current age, some 6 billion years ago. This star was according to NASA about 40 times larger than our sun.

The explosion of the star resulted in a gamma ray burst that originated 7.5 billion light years away from Earth. It has taken these billions of years for the light from that explosion to reach Earth. NASA’s Swift satellite first detected the gamma rays at 2:12 a.m. Wednesday March 18, 2008.

The light from the explosion would have been visible by the naked eye if anyone had been outside to see last week. So bright was the light that it set a new record for the most distant object to be seen from Earth by the naked eye.

CNN quotes Neil Gehrels from NASA as saying, “Someone would have had to run out and look at it with a naked eye, but didn't.” The light would have appeared in the sky as bright as some of the stars in the handle of the Little Dipper constellation according to astronomer David Burrows. Burrow’s says that “This [explosion] is roughly halfway to the edge of the universe.”

Gehrels added that the explosion would have vaporized any planet nearby. Likely, the gamma ray burst would have eradicated anything in its path for thousands of light years. Earth dwellers had little to worry though, as the explosion took place so far away.
A single Polish observatory is the only verified organization to have taken a ground-based image of the gamma ray burst from the supernova.

Source: DailyTech

Laura1013

xCross, could you cite your source when quoting articles? (It's considered plagarism if you don't.) I assume that was from CNN, but I'm not sure.

xCross

had done that.. it's from DailyTech!!

Laura1013

Thank you for adding that.