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Artistic representation of a gamma burst emitted by beams directed in opposite directions after a massive stellar explosion. Although beams are often missing from Earth, these explosions create a revealing transient radio glow that can be detected. (Credit: NRAO)
Mysterious "ghost" radio programs have been spotted by researchers, some of which last 25 years, then disappear and then return. Although "ghost" emissions can be extremely common, the cause is still unknown, experts say.
The assistant astronomer at the University of California Berkeley Research, Casey Law, believes that the broadcasts could be "a reflection of the explosion of a huge star, which would have caused a long-term gamma ray burst not detected ".
"We think we are the first to find evidence of gamma ray bursts that could not be detected with a gamma ray telescope," Law said in a statement. "These are known as" orphan "gamma-ray bursts, and it is expected that many more of these orphaned GRBs will be present in the new radio surveys underway."
WE NEED TO KEEP THE RESEARCH OF ALIANS AND SCIENTISTS SAY TO THE SENATORS
Gamma-ray bursts are very rarely seen in the universe because their source, a stream of relativistic matter emerging from the explosive fusion, must be directed directly to the Earth. The chances of this happening and the NASA Fermi Gamma Ray Space Telescope is about 1%.
The persistence, which can last two and a half decades, could help astronomers find other events like this. This can also help them detect more gamma-ray bursts and understand what happens when a massive stellar explosion occurs and what remains after the explosion.
According to Law, the explosion produces "a fast-spinning, highly magnetized neutron star called magnetar".
The research was published in the journal Astrophysical Journal Letters.
The radio source, FIRST J141918.9 + 394036, is now too weak to be seen in the sky, but it can still be detected by large telescopes. It was first seen by the Very Large Array in New Mexico in the early 90's, when its brightness was maximum.
A MYSTERIOUS RADIO SIGNAL FOUND IN SPACE AND THE ASTRONOMERS DO NOT SAY WHERE IT COMES
"We thought," It was weird, "says Law, evoking the fact that it was still detectable.
"Its maximum brightness in the 90s was quite high, so it's a very big change: reduce the brightness by a factor of about 50. Basically, we went through all the radio surveys, all the radio data sets that we could find, all the archives of the world to reconstruct the history of what happened, "added Law.
Law and his colleagues discovered 10 more radio observations in this part of the sky, which allowed them to find the radio show and then see its disappearance. It is likely that radio broadcasts reached the planet for the first time in 1992 or 1993, the researchers concluded, with maximum brightness coming in 1994. It finally became invisible in 2017, according to the very large 2017 Array Sky Survey .
The object lies 284 million light-years from Earth in a dwarf galaxy forming stars, a phenomenon associated with rapid radio bursts.
SOLID LUMINOUS PLANET ROGUE & # 39; SPOTTED & # 39; DRIFTING & # 39; IN SPACE
"Part of the story is about the amount of sky changing, even in the long run, and the difficulty of testing it," he said. "This also partly concerns the value of new data science techniques. Extracting information from these rich and diverse datasets helps us to do good science. "
Follow Chris Ciaccia on Twitter @Chris_Ciaccia
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