Pasadena, CA. Cosmic gamma-ray bursts produce more energy in the blink of
an eye, than the Sun will release in its entire lifetime. These
short-lived explosions appear to be the death throes of massive stars,
and, many
scientists believe, mark the birth of black holes.Testing these ideas has
been difficult, however, because the bursts fade so quickly and rapid
action is required.Now a team of Carnegie and Caltech astronomers, led by
Carnegie-Princeton and Hubble fellow Edo Berger, has made crucial strides
toward answering these cosmic quandaries.The team was able to discover and
study burst afterglows thanks to the exquisite performance of NASA’s new
Swift satellite and rapid follow-up with telescopes in both the southern
and northern hemispheres.

“I’m thrilled,” said Berger. “We’ve shown that we can chase the Swift
bursts at a moment’s notice, even right before Christmas!This is a great
sign of exciting advances down the road.”The discoveries herald a new era
in the study of gamma-ray bursts, hundreds of which are expected to be
discovered and scrutinized in the next several years.

The Swift satellite detected the first of the four bursts on December 23,
2004, in the constellation Puppis, and Carnegie astronomers used telescopes
at the Las Campanas Observatory in Chile to pinpoint the visual afterglow
within several hours.This was the first burst detected solely by the new
Swift satellite to be pinpointed with sufficient accuracy to study the
remains.The next three bursts came in quick succession between January 17
and 26 and were immediately pinpointed by a team of Carnegie and Caltech
astronomers using the Palomar Mountain 200-inch Hale telescope in
California and the Keck Observatory 10-meter telescopes in Hawai’i.

“The Las Campanas telescopes are ideal for their flexibility to follow up
targets like gamma-ray bursts, which quickly fade out of view,” said
Carnegie Observatories director Wendy Freedman.”This is a wonderful
example of science that comes from the synergy between telescopes on the
ground and in space, and between public and private observatories.”

Because Swift allows a response to new gamma-ray bursts within minutes,
astronomers hope to use the intense light from gamma-ray bursts as cosmic
“flashlights.”They plan to use the bright visual afterglows to trace the
formation of the first galaxies, only a few hundred million years after
the Big Bang, and the composition of the gas that permeates the universe.
“This is much like using a flashlight to study the contents of a dark
room,” said Berger. “But because the flashlight is on for only a few
hours, we have to act quickly.”

“Swift’s rapid response is opening a new window on the universe.I can’t
wait to see what we catch,” remarked Neil Gehrels of Goddard Space Flight
Center, principal investigator for Swift.

Swift, launched on November 20, 2004, is the most sensitive gamma-ray
burst satellite to date, and the first to have X-ray and optical
telescopes on-board, allowing it to relay very accurate and rapid
positions to astronomers on the ground.The satellite is a collaboration
between NASA’s Goddard Space Flight Center, Penn State University,
Leicester University and the Mullard Space Science Laboratory (both in
England), and the Osservatorio Astronomico di Brera in Italy.

In the next few years the Swift satellite is expected to find several
hundred gamma-ray bursts.Follow-up observations on-board Swift and using
telescopes on the ground should move us a few steps closer to answering
some of the most fundamental puzzles in astronomy, such as the birth of
black holes, the first stars, and the first galaxies.

The team that identified and studied the afterglows of the first Swift
bursts–in addition to Berger, Freedman and Gehrels–includes Mario Hamuy,
Wojtek Krzeminski, and Eric Persson from Carnegie Observatories, Shri
Kulkarni, Derek Fox, Alicia Soderberg, and Brad Cenko from Caltech, Dale
Frail from the National Radio Astronomy Observatory, Paul Price from the
University of Hawai’i, Eric Murphy from Yale University, and Swift team
members David Burrows, John Nousek, and Joanne Hill from Penn State
University, Scott Barthelmy from Goddard Space Flight Center, and Alberto
Moretti from Osservatorio Astronomico di Brera.

More information on Swift can be found at:
Information about the Carnegie Observatories is at

The Carnegie Observatories is part of the Carnegie Institution
(, which has been a pioneering force in basic
scientific research since 1902. It is a private, nonprofit organization
with six research departments throughout the U.S. Carnegie scientists are
leaders in plant biology, developmental biology, astronomy, materials
science, global ecology, and Earth and planetary science.