The APF

• UCSC Astronomy Professor Steve Vogt stands inside the dome of the Automated Planet Finder. Photo by Laurie Hatch.

The APF is the world's first robotic telescope capable of detecting rocky planets that might support life in other solar systems.

Extrasolar planetary research has been very successful at Lick Observatory, yet observing time on the Lick Observatory Shane 3-m telescope and Keck 10-m Telescopes for any one project is extremely limited. By operating robotically every on clear night, APF will greatly increase chances of detecting extrasolar planets. APF's more efficient system and higher resolution spectrometer will increase astronomers' ability to detect these planets.

APF consists of a 2.4-meter automated telescope and enclosure, and a high-resolution spectrograph. The telescope and spectrograph will operate robotically every night, like the KAIT. APF will target a preprogrammed list of nearby stars and observe them every night for months, in search of rocky planets with very low masses, similar to Earth. The ultimate goal of extrasolar planet research is to find nearby planets like Earth that may support life.

The spectrograph was designed by UCO's Steve Vogt and built at UCO's Technical Facilities. Named for Gloria and Kenneth Levy, who supported its construction with a generous donation, the spectrograph uses a large camera, diffraction grating, and prism to break up the starlight into over 200,000 distinct colors, and brings all those colors to focus on a CCD. The spectrograph thus produces a very high resolution digital spectrum of the starlight.

The sensitive Levy spectrograph is optimized for speed and radial velocity precision. It will detect velocity changes in each star's movement down to 1 meter per second, equivalent to human walking speed. This change in a star's velocity could indicate that planets are pulling on the star with their gravitational forces. Since the spectrograph detects the smallest possible velocity changes, planets of lowest possible mass can be detected. This enables astronomers to find small rocky earthlike planets. Spectrographic data will be fed into an extrasolar planet data pipeline, which astronomers will then analyze to discover new planets.

Construction of the APF was an international project. The mirror glass was cast and shaped in Russia and optically figured at Rayleigh Optical in Baltimore, MD. The telescope body was assembled in Tucson by EOS. The dome enclosure was fabricated in Australia. The spectrograph was designed and fabricated in California.

To learn more about APF, also known as RPF (Rocky Planet Finder), visit the Rocky Planet Finder website. To learn more about extrasolar planet hunting at Lick Observatory, visit the research page. To learn more about extrasolar planets and research methods, visit the California & Carnegie Exoplanet website.