MT. HAMILTON, CA--Computers soon will take total control of a 30-inch telescope at Lick Observatory, making it the most sensitive fully robotic telescope anywhere.
The Katzman Automatic Imaging Telescope (KAIT), built by astronomers at the University of California, Berkeley, will be dedicated Friday, October 25, by officials from UC Santa Cruz, which operates the observatory atop Mt. Hamilton east of San Jose, California. UCSC Chancellor M.R.C. Greenwood will lead the dedication, which is not open to the public.
The instrument is named for the Sylvia and Jim Katzman Foundation of Saratoga, which donated $50,000 at a critical time in the telescope's development, said Alex Filippenko, professor of astronomy at UC Berkeley and leader of the seven-year effort to build the instrument.
Much of the rest of the funding for KAIT, which totaled about half a million dollars, came from the National Science Foundation in the form of a Presidential Young Investigator Award to Filippenko in 1989.
KAIT will devote itself full-time to checking the night sky for flaring supernovas, to following the changing brightnesses of variable stars, or to observing any object that changes over short or long periods of time. And since it is totally under computer control it can easily be redirected to new targets at an astronomical whim.
The astronomers even hope to give students ready access to the instrument to conduct nightly studies of changing celestial objects, from orbiting moons to comets and asteroids.
"With this telescope, the University of California and Lick Observatory jump to the forefront of research and science education using robotic telescopes," Filippenko said.
"This project fit hand-in-glove with my longtime interests in astronomy and computer engineering," said Jim Katzman, cofounder of Tandem Computers and a member of the Dean's Advisory Council for the Natural Sciences Division at UCSC. "Sylvia and I thought this was a unique and exciting project, because it will allow astronomers to do serious science remotely and to schedule observations that aren't possible with normal telescopes."
KAIT can track a given area of the sky for hours, better than any other robotic telescope now in operation. During a half-hour observation it can detect objects 10,000 times fainter than other such telescopes, or a million times fainter than the human eye can see unaided.
In 1991 Filippenko took over operation of another 30-inch UC Berkeley telescope at Leuschner Observatory that had been automated by astronomers at Lawrence Berkeley Laboratory, but it could not remain fixed on a given star for more than a few minutes. He subsequently modified a 20-inch telescope, also at Leuschner, turning it into a prototype of KAIT called the Berkeley Automatic Imaging Telescope (BAIT).
Both Leuschner telescopes were too old to withstand constant use, however, so Filippenko terminated their robotic capabilities to focus on finishing the new 30-inch automatic telescope at Lick Observatory. Both BAIT and KAIT were constructed with the help of engineer Dick Treffers, who improved and rebuilt much of the purchased instrumentation, and former graduate student Michael Richmond, who contributed to the operations software.
One major difference between KAIT and previous robotic telescopes is the tracking system. KAIT has a separate CCD imaging system for a guide star that allows it to remain precisely fixed on a given area of sky. Other robotic telescopes employ simpler tracking that allows a star to drift significantly in a couple of minutes.
Another key improvement is complex software that makes it easy to orchestrate a night's observing. Targets are entered with a priority number and the computer determines when and how long during the night to look at each one. The computer can automatically change the effective priority of a given target, depending on whether observations were successful in preceding nights. Target requests are sent via email, and data returned via the Internet to the astronomer's computer, or to a school.
The images are captured on electronic film--a CCD camera, like today's camcorders but much better quality, that integrates the amount of light coming through the telescope and spits out a final image at the end of the observation time. Depending on how bright the object is, this could be one second to minutes later, with a practical limit of about half an hour.
Filippenko's main interest is exploding stars or supernovas, which flare suddenly into very bright objects and then dim to obscurity within weeks or months. Capturing the entire process once the supernova is detected requires nightly observation, which on short notice is often impossible to arrange.
"If you want to monitor an exploding star you often have to plead with colleagues for a small amount of time each night, sometimes at telescopes all around the world," he said. "It's not easy to do this, and the data are often of heterogeneous quality in a situation where slight differences are important.
"So I embarked on a project to build an automated, dedicated telescope that could be used for a variety of projects: searching for supernovas, monitoring known variable stars, supernovas and novas, looking at quasars and active galaxies, and very importantly, homing in on targets of opportunity."
One important use of KAIT may be for quick-hit observations. Astronomers frequently need to know how bright an object is so they can estimate how much time to reserve on larger and more expensive telescopes. KAIT can easily accommodate such brief observations.
"I'm already getting requests from people who need to know, for example, the brightness variations of a quasar so they can judge how much time they will need on the Hubble Space Telescope," Filippenko said.
KAIT, located at 1,280 meters elevation, has 20 filters that can be shifted into position automatically for each new observation. Other contributors to the telescope include the University of California, The California Space Institute, Sun Microsystems, Photometrics Ltd., AutoScope Corporation, and Lick Observatory.
Lick Observatory, which opened in 1888, is used by faculty and students throughout the UC system. Its primary observing instrument is the 120-inch Shane Telescope, which began collecting data in 1959. Recently, astronomers Geoffrey Marcy and Paul Butler of San Francisco State University and UC Berkeley used the Shane Telescope and an ultrasensitive device, the Hamilton Spectrograph, to detect evidence of at least half a dozen new planets outside of our solar system.
UC also owns a share of the W. M. Keck Observatory in Hawaii and its 400-inch telescopes, Keck I and Keck II. Both Lick Observatory and UC's share of Keck Observatory are administered by UC Santa Cruz within one unit, UC Observatories/Lick Observatory.
Editor's note: You may reach Alex Filippenko at (510) 642-1813 or firstname.lastname@example.org.