Stellar explosion is most distant and brightest object visible to the naked eyeMarch 21st, 2008 - 3:44 pm ICT by admin
Washington, March 21 (ANI): NASA’s Swift satellite has detected a powerful stellar explosion, which has shattered the record for the most distant object visible to the naked eye and also ranks as the most intrinsically bright object ever observed by humans in the universe.
Previously, the most distant object that could be seen by the naked eye was the nearby galaxy M33, a relatively short 2.9 million light-years from Earth.
According to David Burrows, senior scientist and professor of astronomy and astrophysics at Penn State University, “It’s amazing - we’ve been waiting for a flash this bright from a gamma-ray burst ever since Swift began observing the sky 3 years ago, and now we’ve got one that is so bright that it was visible to the naked eye even though its source is half-way across the universe.”
“Within a 24-hour period, we had an incredible outpouring of activity from the sky 5 Gamma-ray bursts and several other kinds of outbursts - and in the middle of it all, there was the brightest burst we’ve ever seen,” he added.
Gamma-ray bursts are the most luminous explosions in the universe since the Big Bang.
“These optical flashes from gamma-ray bursts are the most extreme such phenomena that we know of,” said Derek Fox, assistant professor of astronomy and astrophysics at Penn State, who confirmed the distance measurement for the burst.
Analysis of the star known as GRB 080319B is just getting underway, so astronomers don’t yet know for sure why this burst and its afterglow were so bright.
Possibly the burst was more energetic than others, perhaps because of the mass, spin, or magnetic field of the collapsing star or its jet. Or perhaps the burst concentrated its energy in a narrow jet that was aimed directly at Earth.
According to Peter Meszaros, Professor of Physics at Penn State University and leader of the theory team for Swift, an unusual combination of circumstances may have contributed to the exceptionally bright afterglow of the burst in the visible wavelengths of light.
“When the jet that formed during the explosion of the star slammed into surrounding gas clouds, shock waves were generated that heated the jet. The exceptional brightness of this burst requires the jet to have just the right combination of magnetic fields and velocity, which occurs very rarely,” he said.
GRB 080319B’s optical afterglow was 2.5 million times more luminous than the most luminous supernova ever recorded, making it the most intrinsically bright object ever observed by humans in the universe. (ANI)
Tags: across the universe, afterglow, astronomy and astrophysics, david burrows, derek fox, distance measurement, distant object, galaxy m33, gamma ray bursts, million light years, naked eye, nasa, nearby galaxy, optical flashes, outpouring, penn state university, peter meszaros, stellar explosion, swift satellite, theory team