The Universe’s Biggest, Baddest Gamma-Ray Burst Ever

A supernova collapse 3.6 billion light-years away sheds new light on a long-standing mystery

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NASA / Getty Images

The Chandra X-ray Observatory and the Hubble Space Telescope show a gamma-ray burst on June 19, 2001

They were first spotted in the late 1960s by satellites designed to ferret out secret thermonuclear tests by the Chinese and Soviets, but some of the bursts of high-energy gamma rays picked up by military spy agencies half a century ago confounded the intelligence community. The blasts weren’t coming from anything as puny as an H-bomb being detonated on the earth below. Instead, scientists eventually realized, they resulted from titanic explosions more than halfway across the universe.

By now, astrophysicists generally understand these gamma-ray bursts, or GRBs, which pop off once a day, on average, and are most likely triggered by supernovae, or exploding stars. But the details are still sketchy, which is why a new burst seen in the constellation Leo by two different NASA satellites, the Swift mission and the Fermi Gamma-ray Space Telescope, is so potentially important: it’s by far the most vivid event ever seen — “eye-wateringly bright,” according Fermi project scientist Julie McEnery. That means follow-up observations will be unusually easy to do — and those kinds of aftershock studies are where the real work gets done.

In the past, follow-up analyses were what helped astronomers figure out what causes GRBs in the first place. The only clues they had back in the 1990s, thanks to the important but limited insight provided by NASA’s now defunct Compton Gamma Ray Observatory, was that the bursts seemed to come randomly from all directions in the sky.

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That meant they couldn’t be originating mostly in the Milky Way, which spreads outward in a disk shape, not in all directions like a sphere. The only two things that completely surround earth that way are the outer reaches of the solar system — where the Oort cloud of comets lives — and the cosmos itself. GRBs are hardly likely to come from comets — dirty snowballs of ice and rock — which leaves the cosmos as the only plausible source. Eventually, observers managed to aim telescopes in the direction of GRBs very shortly after they popped off, and spotted an afterglow of X-ray and optical light in the very same spot. That is the fingerprint of a supernova, so one part of the mystery was solved; but the exact mechanism behind the phenomenon was still uncertain.

At present, the best explanation for that piece is that a giant, aging star collapses abruptly to form a black hole. Some of the remaining material is shot outward to form a rapidly expanding shell of gas. Some gas also falls into the black hole, where it’s compressed and heated, and sometimes shoots a jet of matter back outward. When the jet runs into the expanding shell of gas, it triggers a cataclysmic explosion — and the result is a GRB. It probably happens when any supermassive star collapses to form a black hole, but, says McEnery, “we’re not going to see most of them; we can only detect them when the jets point right at us.”

The value of the newest, biggest burst is that it is also the best opportunity to refine and improve the existing theory. Technically, this one isn’t actually the brightest GRB detected in absolute terms: some have been more dazzling, but so far away that they’ve seemed relatively dim. This one, known as GRB 130427A, was a “mere” 3.6 billion light-years away — still far, far beyond the edges of the Milky Way, but close enough, says McEnery, that “it outshone everything else in the night sky for several seconds.”

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That brightness is allowing the scientists to dissect the burst in unprecedented detail, which could help them understand some of the still murky details of how supernovas unfold. In fact, says McEnery, “we can study this event in ways we could never dreamed of. We’re likely to be seeing the afterglow for several months.”

That’s the formal scientific explanation for her obvious excitement, and that of GRB watchers and supernova theorists around the world. Then there’s the informal explanation: “Stuff that blows up,” she says. “What’s not to like?”

PHOTOS: Explosions in the Sky: The Cygnus Loop Nebula

6 comments
kevin1981
kevin1981

NASA, in five bilion years will our sun go gamma on us or will it explode into a red giant like NASA says?  I can't see any life form survive the most destructive explsion in the universe. You don't have to be in the beams. Just being near the burst it is so hot planets that are millions of light years away are turned into dust.  How can any life form including ET survive the intesense heat and radiation.  We have learned a great deal about gamma ray bursts but they concern me the most more than an asteroid or comet. WE might be able to deflect a comet or asteroid but not a gamma ray burst TIME. The entire galaxy would be wiped out and incinerated by temperatures heating ALL planets there up a million degrees. NO CHANCE and I hope President Obama's science advisors are telling him the same thing I am at the white house.  You don't have to be in the path of the beams mr.president.

kevin1981
kevin1981

Mankind, I CAN'T BELIEVE WE CAN DETECT GAMMA RAY BURSTS FROM BILLIONS OF LIGHT YEARS AWAY. That is very far,far,far away. There is no chance planets in that galaxy would survive a burst. The intense heat and radiation would kill any life form incuding ET on CONTACT in seconds. WHO or what can survive a burst with a million trillion suns exploding. That is very, very HOT mankind.  If there was aliens out there they are getting killed. I feel bad for them than us. I wish we treated each other with more respect becuase we have no idea how good we got it compared to other galaxies. They are ALL dead.

kevin1981
kevin1981

Time,, did God made the universe for binary stars and neutron stars to wipe out galaxies with millions of species. NO! I am not a scientist but I am telling everybody stop searching the cosmos because aliens are extinct becuase of these massive and I mean massive explosions across the universe. Our satellites can detect them from beyond forever imagine standing on an earthlike planet there that day in that galaxy aand at the moment we detect the burst imagine what's happening. You see the most blinding white light and then three to four seconds of extreme pain you're dead. That is what is happening out there when stars explode and the beams travel at the speed of light across the universe. Everything and everyone is dead right now so by having the largest radio telescope is a complete waste of time mankind. I wonder what President Obama thinks?  We are the luckiest species in the universe.

kevin1981
kevin1981

Time, can you imagine a gamma ray burst was to happen in our galaxy? It is the end of life as we know it. A million trillion suns would incinerate the entire galaxy and I believe they are wiping out the entire universe. NASA is detecting one burst a day from across imagine what is happening on planets right in the bursts path. The planet's ozone is destroyed and thei roxygen supply is shortened and immmense heat on th eplanet. the planet would heat up a million degrees and that's the end of civilization. I studied astronomy in school and I CAN'T BELIEVE how powerful they are. I believe now WE are all alone because of gamma ray bursts and quasars, anybody disagree?

david1268
david1268

Did the IceCube Neutrino Observatory at the South Pole detect a neutrino pulse associated with this event?  I'm not sure if that's possible with such a distant SN.

Aphugel
Aphugel like.author.displayName 1 Like

"EVER"..... no comment............