Swift Satellite Detects Unusual Cosmic Explosion (Forwarded)

Office of Public Information
Eberly College of Science
Pennsylvania State University
University Park, Pennsylvania

SWIFT SCIENCE CONTACT AT PENN STATE:

John Nousek
Director of the Swift Mission Operations Center
and
Professor of astronomy and astrophysic
(+1)814-865-7747

Derek Fox
Assistant professor of astronomy and aastrophysics
(+1)814-863-4989

P.I.O. CONTACTS:

Barbara K. Kennedy (Penn State PIO)
(+1)814-863-4682

Susan Hendrix (NASA PIO)
(+1)301-286-0040

Lynn Cominsky (Swift PIO)
(+1)707-664-2655

24 February 2006

Swift Satellite Detects Unusual Cosmic Explosion

The Swift satellite, whose mission control center is in State College,
has detected a cosmic explosion that has sent scientists around the
world scrambling to telescopes to document this startling event.
Gamma-ray radiation from the source, detected on 18 February and lasting
about half an hour, appears to be a precursor to a supernova, which is
the death throes of a star much more massive than the Sun. "The
observations indicate that this is an incredibly rare glimpse of an
initial gamma-ray burst at the beginning of a supernova," said Peter
Brown, a Penn State graduate student and a member of the Swift science team.

Astronomers are using Swift, whose science and flight operations are
controlled by Penn State from the Mission Operations Center in State
College, to continue to observe the event. Scores of satellites and
ground-based telescopes also are now trained on the sight, watching and
waiting. Amateur astronomers in the northern hemisphere with a good
telescope in dark skies also can view the source.

The explosion has the trappings of a gamma-ray burst, the most distant
and powerful type of explosion known. This event, however, was about 25
times closer and 100 times longer than the typical gamma-ray burst.
"This burst is totally new and unexpected," said Neil Gehrels, Swift
principal investigator at NASA's Goddard Space Flight Center in
Greenbelt, Maryland. "This is the type of unscripted event in our nearby
universe that we hoped Swift could catch."

The explosion, called GRB 060218 after the date it was discovered,
originated in a star-forming galaxy about 440 million light-years away
toward the constellation Aries. This is the second-closest gamma-ray
burst ever detected, if indeed it is a true burst.

Derek Fox, assistant professor of astronomy and astrophysics at Penn
State, who is leading the monitoring effort of GRB 060218 on the
Hobby-EberlyTelescope, commented, "This is the burst we've been waiting
eight years for," referring to the closest-ever gamma-ray burst, which
was detected in 1998. "The special capabilities of Swift, which was not
operating in 1998, combined with the intense campaign of ground-based
telescopes, should help unravel this mystery," said Fox.

"There are still many unknowns," said Penn State Professor of Astronomy
and Astrophysics John Nousek, the Swift mission operations director at
Penn State University in University Park, Pennsylvania. The burst of
gamma rays lasted for nearly 2,000 seconds; in contrast, most such
bursts last a few milliseconds to tens of seconds. The explosion also
was surprisingly dim. "This could be a new kind of burst, or we might be
seeing a gamma-ray burst from an entirely different angle," he said. The
standard theory for gamma-ray bursts is that the high-energy light is
beamed in our direction. "This off-angle glance -- a profile view,
perhaps -- has given us an entirely new approach to studying star
explosions. Had this burst been farther away, we would have missed it,"
Nousek explained.

Because the burst was so long, Swift was able to observe the bulk of the
explosion with all three of its instruments: the Burst Alert Telescope,
which detected the burst; and the X-ray Telescope, and
Ultraviolet/Optical Telescope, which provide high-resolution imagery and
spectra across a broad range of wavelengths. Penn State lead the
development of the X-ray and Ultraviolet/Optical Telescopes.

Scientists will attempt observations with the Hubble Space Telescope and
the Chandra X-ray Observatory. Amateur astronomers in dark skies might
be able to see the explosion with a 16-inch telescope as it hits
16th-magnitude brightness.

Swift is a NASA mission in partnership with the Italian Space Agency and
the Particle Physics and Astronomy Research Council in the United
Kingdom; it is managed by NASA Goddard, and Penn State controls its
science and flight operations from the Mission Operations Center in
University Park, Pennsylvania.

ABOUT SWIFT:

Swift was launched in November 2004 and was fully operational by January
2005. Swift carries three main instruments: the Burst Alert Telescope,
the X-ray Telescope, and the Ultraviolet/Optical Telescope. Swift's
gamma-ray detector, the Burst Alert Telescope, provides the rapid
initial location and was built primarily by the NASA Goddard Space
Flight Center in Greenbelt and Los Alamos National Laboratory and
constructed at GSFC. Swift's X-Ray Telescope and UV/Optical Telescope
were developed and built by international teams led by Penn State and
drew heavily on each institution's experience with previous space
missions. The X-ray Telescope resulted from Penn State's collaboration
with the University of Leicester in England and the Brera Astronomical
Observatory in Italy, and the Ultraviolet/Optical Telescope from a
collaboration with the Mullard Space Science Laboratory of the
University College-London. These three telescopes give Swift the ability
to do almost immediate follow-up observations of most gamma-ray bursts
because Swift can rotate so quickly to point toward the source of the
gamma-ray signal.

IMAGE CAPTIONS:

[Movie:
http://www.science.psu.edu/alert/vid...Animation.mpeg
(3.9MB)]
The collapsing star scenario that is one of the leading contenders as
the cause of gamma-ray bursts. Dr. Stan Woosley of the University of
California at Santa Cruz proposed the collapsar theory in 1993. This
artist's concept of the collapsar model shows the center of a dying star
collapsing minutes before the star implodes and emits a gamma-ray burst
that is seen across the universe.

Credit: NASA/Dana Berry

[Image:
http://www.science.psu.edu/alert/Ima...ll_grb_LRG.jpg
(3.6MB)]
Scientists are studying a strange explosion that appeared on February
18, 2006, about 440 million light years away in the constellation Aries.
The "before" image on the left is from the Sloan Digital Sky Survey. The
"after" image on the right is from NASA Swift's Ultraviolet/Optical
Telescope. The pinpoint of light from this star explosion outshines the
entire host galaxy. Most other sources are foreground stars. Each image
is 5 arcminutes by 5 arcminutes. Coordinates for this burst are as
follows: RA: 03:21:39.71 Dec: +16:52:02.6

Credit: SDSS (left), NASA/Swift/UVOT (right)