The birth cry of a black hole has startled University of Chicago
astrophysicists and their colleagues who operate a NASA satellite
that searches for gamma-ray bursts, the most powerful explosions in
the universe.

Now the Chicago astrophysicists are rushing to make follow-up
observations of the event with the Astrophysical Research Consortium
3.5-meter telescope at the Apache Point Observatory in New Mexico.
They also are drowning in information provided by amateur astronomers.

“This event is so bright that hundreds of amateur astronomers
have been observing it, recording their data and providing it to us,”
said Don Lamb Jr., the Louis Block Professor in Astronomy &
Astrophysics at the University of Chicago and Mission Scientist for
the HETE-2 mission. “We can’t keep up with it.”

Gamma-ray bursts signal the birth of black holes, which are
objects so dense that no light can escape their gravitational pull.
The burst detected by NASA’s High Energy Transient Explorer-2
satellite on the morning of March 29 was one of the brightest and
closest every reliably documented, Lamb said.

“This could nail the connection between gamma-ray bursts and
core-collapse supernovae,” he said. This type of supernova, or
exploding star, results in the formation of a black hole.

The data suggest that the supernova explosion was very
non-spherical, which supports new ideas about how core collapse
supernovae happen. “This is absolutely going to change everything,”
Lamb said.

The burst, designated GRB 030329, lasted for more than 30
seconds. Only two other gamma-ray bursts have shined more brightly in
the 30 years since the phenomenon was discovered, Lamb said. Even its
afterglow shined more than 10,000 times brighter than its host galaxy
two hours after the burst occurred.

The explosion occurred approximately 2 billion light years from
Earth, too distant to pose a threat, but two and a half times closer
than the next-closest burst for which scientists have reliable
measurements.

HETE-2 is pinpointing the positions on the sky of 25 gamma-ray
bursts annually. “The chance of a burst this near and this bright
happening is one in a few thousand,” Lamb said. “We likely won’t see
anything like this again.”

Collaborating with Lamb on HETE-2 are the University of Chicago’s
Carlo Graziani, Senior Research Associate in Astronomy &
Astrophysics, and Timothy Donagy, a graduate student in Physics.
Collaborating with him on the follow-up observations are Donald York,
the Horace B. Horton Professor in Astronomy & Astrophysics at the
University of Chicago, and John Barentine and Russet McMillan,
Observing Specialists at Apache Point Observatory.