The world’s largest astronomical camera has been
installed on Palomar Observatory’s 48-inch Oschin Telescope in
California. This telescope has been working to improve our understanding
of the universe for nearly 55 years. The new upgrade will help it to
push the limits of the unknown for years to come.
The new camera is known as QUEST (Quasar Equatorial Survey Team).
Designed and built by astrophysicists at Indiana and Yale universities,
QUEST recently “saw” its first starlight and is now scanning the sky.
In 2001, an electronic camera known as the Near-Earth Asteroid Tracker
was installed in the Oschin Telescope. The camera, which employed a
charge-coupled device (CCD) to detect light, was very successful. During
its tenure on Palomar, the NEAT team discovered 189 near-Earth asteroids
and 20 comets.
A charge-coupled device is a light-sensitive integrated circuit that
stores and displays the data for an image in such a way that each pixel
in the image is converted into an electrical charge whose intensity is
related to a color in the visual spectrum. The QUEST camera has an array
of 112 CCDs.
The Oschin Telescope had to undergo some major changes to accommodate
the QUEST camera. Under the oversight of Richard Ellis, director of
Palomar Observatory, this process was guided by Robert Thicksten and Hal
Petrie of the California Institute of Technology. The delicate
installation of the camera and its electronics inside the telescope was
handled by Mark Gebhard (Indiana University), William Emmet (Yale
University) and David Rabinowitz (Yale University). The camera’s readout
electronics were constructed in the Physics and Astronomy departments at
Indiana University by Gebhard and Brice Adams, under the direction of
James Musser, Kent Honeycutt and Stuart Mufson. The hardware for the
QUEST camera was constructed by the Yale University Physics Department
under the direction of Charles Baltay.
In addition to the usual point-and-shoot mode, the new camera is
designed to work in the drift scan mode. The telescope is pointed at the
sky but does not move to counteract the rotation of the Earth. Instead,
various objects in the sky gradually drift across the field of view at
the same rate as the computer records data from the CCDs, producing
photographs that are long strips of the sky. Astronomers will use these
photographic slices of the sky to look for quasars, supernovae,
asteroids and more.
Last year, Caltech astronomers Chad Trujillo and Mike Brown used the
NEAT camera on the Oschin Telescope to find the distant world known as
Quaoar. Quaoar is about half the size of Pluto, making it the biggest
object to be found in our solar system since Pluto was discovered in
1930. Quaoar is the largest known member of the Kuiper Belt, a swarm of
thousands of icy objects that orbit beyond Neptune. Brown is convinced
there are more big Kuiper Belt objects, possibly as big as the planet
Mars, and he will use QUEST to look for them.
Other scientists plan to use the camera to find objects that might be
quasars. Quasars are the very bright cores of distant galaxies that are
thought to contain supermassive black holes. They are among the most
luminous objects in the universe. Any quasar candidates that are found
with the Oschin Telescope will be looked at again with Palomar’s
200-inch Hale Telescope. Those objects that the Hale Telescope confirms
to be quasars will be the targets of more detailed study with one of the
10-meter Keck Telescopes in Hawaii.
A similar approach will be used as distant galaxies are probed in a
search for exploding stars known as supernovae. The QUEST camera will do
the survey work, suspected supernovae will be looked at with the Hale
Telescope, and supernovae of the right type will be scrutinized at one
of the Keck Telescopes. Astronomers will use data from these exploding
stars to try to confirm that the universe is accelerating as it expands.
Palomar Observatory, owned and operated by the California Institute of
Technology and located in north San Diego County, Calif., supports the
research of Caltech faculty and students, and that of researchers at
Caltech’s collaborating institutions: Indiana University, Cornell
University, Yale University and the Jet Propulsion Laboratory.
For more information, contact James Musser at 812-855-9933,
http://newsinfo.iu.edu/news/page/print/982.html
Related Information
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Media Contacts:
James Musser
Hal Kibbey
Related Links:
James Musser http://www.physics.indiana.edu/faculty/Musser.shtml
Kent Honeycutt http://www.astro.indiana.edu/honeycutt/vita.html
Palomar Observatory
musser@bigbang.astro.indiana.edu
812-855-6916, honey@astro.indiana.edu
IU Department of Physics
812-855-9933
musser@bigbang.astro.indiana.edu
IU Media Relations
812-855-0074
hkibbey@indiana.edu
http://www.astro.caltech.edu/observatories/palomar/
