As you see from the post dates, this blog is no longer maintained.

26.3.08

"This blows away every gamma ray burst we've seen so far."

On March 21, 2008, NASA Science writes about a powerful gamma ray burst detected on March 19th by NASA's Swift satellite. The burst was so large it has shattered the record for the most distant object that could be seen with the naked eye. The burst, named "GRB 080319B", was one of four bursts that Swift detected that day, a Swift record for one day. (The quotation in this post's title is from Neil Gehrels of NASA's Goddard Space Flight Center.)


This photo shows GRB 080319B, among the stars of the constellation Bootes in a movie made by "Pi of the Sky", a Polish group that monitors the sky for afterglows and other short-lived phenomena. (You'll see the burst is right in the middle of the picture)
"Most gamma ray bursts occur when massive stars run out of nuclear fuel. Their cores collapse to form black holes or neutron stars, releasing an intense burst of high-energy gamma rays and ejecting particle jets that rip through space at nearly the speed of light. When the jets plow into surrounding interstellar clouds, they heat the gas to incandescent visibility. It is this gaseous "afterglow" which was visible to the human eye on March 19th." (link)
The redshift of the burst was measured at 0.94 (A redshift s a measure of the distance to an object.
"A redshift of 0.94 translates into a distance of 7.5 billion light years,meaning the explosion took place 7.5 billion years ago, a time when the universe was less than half its current age and Earth had yet to form. This is more than halfway across the visible universe." (link)
Read the whole story here (Science@NASA), and more about gamma rays here.
The Swift satellite is managed by NASA's Goddard Space Flight Center. It was built and is being operated in collaboration with Penn State, the Los Alamos National Laboratory, and General Dynamics in the U.S.; the University of Leicester and Mullard Space Sciences Laboratory in the United Kingdom; Brera Observatory and the Italian Space Agency in Italy; plus partners in Germany and Japan.