New Gamma-Ray Burst Smashes Cosmic Distance Record
“Swift was designed to catch these very distant bursts,” said Swift lead scientist
“The burst most likely arose from the explosion of a massive star,” said
Gamma-ray bursts are the universe’s most luminous explosions. Most occur when massive stars run out of nuclear fuel. As their cores collapse into a black hole or neutron star, gas jets — driven by processes not fully understood — punch through the star and blast into space. There, they strike gas previously shed by the star and heat it, which generates short-lived afterglows in many wavelengths.
“The lack of visible light alone suggested this could be a very distant object,” explained team member Edo Berger of
Beyond a certain distance, the expansion of the universe shifts all optical emission into longer infrared wavelengths. While a star’s ultraviolet light could be similarly shifted into the visible region, ultraviolet-absorbing hydrogen gas grows thicker at earlier times. “If you look far enough away, you can’t see visible light from any object,” he noted.
Within three hours of the burst,
At the same time, Fox led an effort to obtain infrared images of the afterglow using the Gemini North Telescope on
As Fox spread the word about the record distance, telescopes around the world slewed toward GRB 090423 to observe the afterglow before it faded away.
At the Galileo National Telescope on La Palma in the Canary Islands, a team including
“It’s an incredible find,” Chincarini said. “What makes it even better is that a telescope named for Galileo made this measurement during the year in which we celebrate the 400th anniversary of Galileo’s first astronomical use of the telescope.”
A few hours later, Tanvir’s team confirmed the distance using one of the European Very Large Telescopes on
The previous record holder was a burst seen in
NASA’s Goddard Space Flight Center manages Swift. It was built and is being operated in collaboration with
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