Palomar Begins a New Sky Survey

Image credit: Caltech

The Palomar Observatory has begun a new survey of the sky, and will explore the Universe from our solar system out to distant quasars, 10 billion light-years away. The survey will be done with the refurbished 48-inch Oschin telescope with a newly attached digital CCD camera – the largest ever built with 112 separate detectors. The researchers plan to publish images gathered by the telescope onto the web so that other astronomers can search the data for near-earth asteroids, Kuiper Belt objects, supernovae and other objects.

A major new sky survey has begun at the Palomar Observatory. The Palomar-QUEST survey, a collaborative venture between the California Institute of Technology, Yale University, the Jet Propulsion Laboratory, and Indiana University, will explore the universe from our solar system out to the most distant quasars, more than 10 billion light-years away.

The survey will be done using the newly refurbished 48-inch Oschin Telescope, originally used to produce major photographic sky atlases starting in 1950s. At its new technological heart is a very special, fully digital camera. The camera contains 112 digital imaging detectors, known as charge-coupled devices (CCDs). The largest astronomical camera until now has had 30 CCDs. CCDs are often used for digital imaging ranging from common snapshot cameras to sophisticated scientific instruments. Designed and built by scientists at Yale and Indiana Universities, the QUEST (Quasar Equatorial Survey Team) camera was recently installed on the Oschin Telescope. “We are excited by the new data we are starting to obtain from the Palomar Observatory with the new QUEST camera,” says Charles Baltay, Higgins Professor of Physics and Astronomy at Yale University. Baltay’s dream of building a large electronic camera that could capture the entire field of view of a wide-field telescope is now a reality. The survey will generate astronomical data at an unprecedented rate, about one terabyte per month; a terabyte is a million megabytes, an amount of information approximately equivalent to that contained in two million books. In two years, the survey will generate an amount of information about equal to that in the entire Library of Congress.

A major new feature of the Palomar-QUEST survey will be many repeated observations of the same portions of the sky, enabling researchers to find not only objects that move (like asteroids or comets), but also objects that vary in brightness, such as the supernova explosions, variable stars, quasars, or cosmic gamma-ray bursts–and to do this at an unprecedented scale.

“Previous sky surveys provided essentially digital snapshots of the sky”, says S. George Djorgovski, professor of astronomy at Caltech. “Now we are starting to make digital movies of the universe.” Djorgovski and his team, in collaboration with the Yale group, are also planning to use the survey to discover large numbers of very distant quasars–highly luminous objects believed to be powered by massive black holes in the centers of young galaxies–and to use them to probe the early stages of the universe.

Richard Ellis, Steele Professor of Astronomy and director of the Caltech Optical Observatories, will use QUEST in the search for exploding stars, known as supernovae. He and his team, in conjunction with the group from Yale, will use their observations of these exploding stars in an attempt to confirm or deny the recent finding that our universe is accelerating as it expands.

Shri Kulkarni, MacArthur Professor of Astronomy and Planetary Science at Caltech, studies gamma-ray bursts, the most energetic stellar explosions in the cosmos. They are short lived and unpredictable. When a gamma-ray burst is detected its exact location in the sky is uncertain. The automated Oschin Telescope, armed with the QUEST camera’s wide field of view, is poised and ready to pin down the exact location of these explosions, allowing astronomers to catch and study the fading glows of the gamma-ray bursts as they occur.

Closer to home, Caltech associate professor of planetary astronomy Mike Brown is looking for objects at the edge of our solar system, in the icy swarm known as the Kuiper Belt. Brown is convinced that there big objects out there, possibly as big as the planet Mars. He, in collaboration with astronomer David Rabinowitz of Yale, will use QUEST to look for them.

Steve Pravdo, project manager for the Jet Propulsion Laboratory’s Near-Earth Asteroid Tracking (NEAT) Project, will use QUEST to continue the NEAT search which began in 2001. The QUEST camera will extend the search for asteroids that might one day approach or even collide with our planet.

The Palomar-QUEST survey will undoubtedly enable many other kinds of scientific investigations in the years to come. The intent is to make all of the copious amounts of data publicly available in due time on the Web, as a part of the nascent National Virtual Observatory. Roy Williams, member of the professional staff of Caltech’s Center for Advanced Computing Research, is working on the National Virtual Observatory project, which will greatly increase the scientific impact of the data and ease its use for public and educational outreach as well.

The QUEST team members from Indiana University are Jim Musser, Stu Mufson, Kent Honeycutt, Mark Gebhard, and Brice Adams. Yale University’s team includes Charles Baltay, David Rabinowitz, Jeff Snyder, Nick Morgan, Nan Ellman, William Emmet, and Thomas Hurteau. The members from the California Institute of Technology are S. George Djorgovski, Richard Ellis, Ashish Mahabal, and Roy Williams. The Near-Earth Asteroid Tracking team from the Jet Propulsion Laboratory consists of Raymond Bambery, principal investigator, and coinvestigators Michael Hicks, Kenneth Lawrence, Daniel MacDonald, and Steven Pravdo.

Installation of the QUEST camera at the Palomar Observatory was overseen by Robert Brucato, Robert Thicksten, and Hal Petrie.

Original Source: Caltech News Release