Press Release

Amateur astronomer locates powerful stellar explostion before the pros

By SpaceRef Editor
August 13, 2003
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Armed with a 12-inch telescope, a computer, and a NASA email alert, Berto Monard
of South Africa has become the first amateur astronomer to discover an afterglow
of a gamma-ray burst, the most powerful explosion known in the Universe.

The discovery highlights the ease in tapping into NASA’s burst alert system, as
well as the increasing importance that astronomy enthusiasts play in helping
scientists understand fleeting and random events, such as star explosions and
gamma-ray bursts.

This 40-second-long burst was detected by NASA’s High-Energy Transient Explorer
(HETE) on July 25. Monard’s positioning of the lingering afterglow, and thus
burst location, has given way to precision follow-up study, an opportunity that
very well might have been missed: At the time of the burst, thousands of
professional astronomers were attending the International Astronomical Union
conference in Sydney, Australia, far away from their observatories.

"I have seen a multitude of stars and galaxies and even supernovae, but this
gamma-ray burst afterglow is among the most ancient light that has ever graced
my telescope," Monard said. "The explosion that caused this likely occurred
billions of years ago, before the Earth was formed."

Gamma-ray bursts, many of which now appear to be massive star explosions
billions of light years away, only last for a few milliseconds to upwards of a
minute. Prompt identification of an afterglow, which can last for hours to days
in lower-energy light such as X ray and optical, is crucial for piecing together
the explosion that caused the burst.

Monard notified the pros of the burst location within seven hours of the HETE
detection. The Interplanetary Network (IPN), comprising six orbiting gamma-ray
detectors, confirmed the location shortly thereafter.

Because of the nature of gamma-ray light, which cannot be focused like optical
light, HETE locates bursts to only within a few arcminutes. (An arcminute is
about the size of an eye of a needle held at arm’s length.) Most gamma-ray
bursts are exceedingly far, so myriad stars and galaxies fill that tiny circle.
Without prompt localization of a bright and fading afterglow, scientists have
great difficulty locating the gamma-ray burst location days or weeks later.

The study of gamma-ray bursts (and increasing ease of amateur participation)
comes through two innovations: faster burst detectors like HETE and a
near-instant information relay system called the Gamma-ray Burst Coordinates
Network, or GCN, which is located at NASA Goddard Space Flight Center in
Greenbelt, Md.

The typical pattern follows: HETE detects a burst and, within a few seconds to
about a minute, relays a location to the GCN. Instantly, the automated GCN
notifies scientists and amateur astronomers worldwide about the burst event via
email, pagers, and a Web site.

Monard is a member of the American Association of Variable Star Observers
(AAVSO). This organization operates the AAVSO International High Energy Network,
which acts as a liaison between the amateur and the professional communities.
Monard essentially used GCN information passed through the AAVSO and other
network groups and turned his telescope to the location determined by HETE.

"In the past two years, HETE has opened the door wide for rapid follow-up
studies by professional astronomers," said HETE Principal Investigator George
Ricker of MIT. "Now, with GRB030725, the worldwide community of dedicated and
expert amateur astronomers coordinated through the AAVSO is leaping through that
door to join the fun."

Monard, a Belgian national living in South Africa, has other discoveries under
his belt, including ten supernovae and several outbursts from neutron star
systems, as part of his participation with the worldwide Center for Backyard
Astrophysics network and the Variable Star Network.

The AAVSO, founded in 1911, is a non-profit, scientific organization with
members in 46 countries. It coordinates, compiles, digitizes and disseminates
observations on stars that change in brightness (variable stars) to researchers
and educators worldwide. Its International High Energy Network was created with
cooperation from NASA.

HETE was built by the Massachusetts Institute of Technology under NASA’s
Explorer Program. HETE is a collaboration among NASA, MIT, Los Alamos National
Laboratory; France’s Centre National d’Etudes Spatiales, Centre d’Etude Spatiale
des Rayonnements, and Ecole Nationale Superieure de l’Aeronautique et de
l’Espace; and Japan’s Institute of Physical and Chemical Research (RIKEN). The
science team includes members from the University of California (Berkeley and
Santa Cruz) and the University of Chicago, as well as from Brazil, India and Italy.

For more information on NASA please consult the following website:
http://www.nasa.gov

Interested amateurs are encouraged to sign up for the network through the AAVSO
web site at:
http://www.aavso.org

SpaceRef staff editor.