Scientists claim to have solved one of the main mysteries of astronomy - the origin of the massive gamma ray bursts.
Avi Blizovsky
On the left - the area in the sky before the eruption and on the right after it. In the bottom picture - the multi-mirror telescope from Arizona
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Update 27/4 - the Israeli connection
The prediction was successful, the supernova was seen
A team of theoretical physicists from the Technion in Haifa and Saran developed a theory for measuring and precisely calculating the mysterious gamma radiation bursts - an event that is associated with a supernova, the explosion of a star in the depths of the universe.
The Israeli team included Prof. Arnon Der and Shlomo Dado and the physicist Dr. Alvaro de Rojula from the Serzan Institute for Nuclear Research. On March 29, a burst of gamma radiation was observed in the telescopes - and the team predicted that the light of the supernova would first be seen on Earth only on April 8 - and it was. Two 6.50 meter "Magellan" MMTO telescopes of the American Harvard University, and other institutes, "captured" the Spurnova.
This is the first time that physicists have predicted the exact day for this. So far, they said, the level of accuracy in such a prediction for the needs of astronomy was a million years.
The research demonstrated the possibility of connecting two different fields of physics - particle physics and the science of cosmology.
Scientists claim to have solved one of the main mysteries of astronomy - the origin of the massive gamma ray bursts. For a few seconds, one burst of gamma radiation can outlast everything else in the universe. About once a day a flash of high-energy radiation comes from deep space and lasts a few seconds. These flashes are often observed by satellites making observations outside the Earth's atmosphere. The sheer power of these eruptions has amazed astronomers for some time.
Now, thanks to an eruption that was close in cosmic terms, the riddle of their nature may be solved. The outburst appears to have simply come from stars exploding as supernovae.
"Now there should be no doubt in anyone's heart that gamma-ray bursts and supernovae are related to each other," says Thomas Matheson of the Harvard-Smithsonian Center for Astrophysics, a member of the team responsible for the discovery.
In the late XNUMXs, an American military satellite designed to locate nuclear tests received enormous bursts of radiation coming from deep space. These bursts seem to come from outside our galaxy, from distances already comparable to the order of magnitude of the universe itself.
However, since the eruptions come from such a distance, it means that the energy they release is enormous and astronomers have struggled to explain it.
Several theories have been proposed including collisions between black holes or neutron stars that could release a tremendous amount of energy. However, none of the explanations were completely satisfactory.
Technological improvements allowed astronomers to react quickly to these elusive events and point their telescopes at the event while it was happening, when they were able to detect a fading glow from that strange object.
The outburst began on March 29 when the HETE (High-Energy Transient Explorer) satellite detected one of the brightest and closest bursts of gamma rays ever seen.
The outburst lasted 30 seconds in the direction of the Leo group and was named GRB 030329 in the meantime, and it shone like the rest of the universe in the gamma ray spectrum. Its optical appearance was still a trillion times stronger than the Sun, over two hours later.
After news of the eruption spread around the world, astronomers working at the 6.5-foot (XNUMX m) multi-mirror observatory on Arizona's Mount Hopkins were able to stop their scheduled work and look at the eruption.
"We caught him in the act," Matheson said. "The eruption was approximately two billion light-years from Earth, unlike the other eruptions that are 10 billion light-years away.
For the first time we were able to see an event that the human eye had not been able to see before," added Krzysztof Stanak from Harvard. "The multi-view telescope has been our miracle instrument that we use to capture these catastrophic events."
The astronomers discovered direct evidence that the afterglow showed the same patterns as light from the supernova.
A supernova is an exploding star that is at least 8 times more massive than the Sun. When such stars exhaust their nuclear fuel, they no longer have the energy needed to support their mass. Therefore their nucleus explodes, creating a neutron star or if it is massive enough - a black hole. The outer atmosphere erupts into space.
At the moment the researchers cannot determine the timing of the gamma ray burst in relation to the supernova (does one of them cause the other or do they both start at the same time), however in the same event - the explosion of a star was surely the trigger for both, they say.
All gamma-ray bursts are likely related to supernovae that were too faint to see, said Matheson, who believes that because the burst was both close and bright, the supernova could be seen. It was a detailed observation of what was left after the scrambling the following night that led to the vital clue. In the fading light, the astronomers observed the tell-tale signs. The mystery is apparently solved," he said.
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