Automated Planet Finder, Robotic telescope at Mount Hamilton, United States

The Automated Planet Finder is a fully robotic 2.4-metre optical telescope at Lick Observatory on the summit of Mount Hamilton, east of San Jose, California. Its mirror blank was cast in Russia, figured in Maryland, assembled in Arizona, and the dome was built in Australia. The Ken and Gloria Levy Doppler Spectrometer measures stellar radial-velocity shifts down to about one metre per second, aiming at stars within roughly 100 light years.

First light was planned for 2006, but delays in building the telescope's main components pushed commissioning to August 2013. Its mirror blank was cast in Russia, figured in Maryland, the assembly done in Arizona, the dome built in Australia and the Ken and Gloria Levy Doppler Spectrometer designed and built in California. The estimated cost was $10 million; the project cost $12.37 million to complete.

The APF also carries out a SETI programme: it searches for optical laser signals from hypothetical extraterrestrial civilisations, a task funded through the Breakthrough Listen project of the Berkeley SETI Research Center. Its Ken and Gloria Levy Doppler Spectrometer was designed and built in California.

The facility operates automatically at night without requiring manual adjustments, since the system works independently once activated. Visitors should keep in mind that the observatory sits at high elevation and may be closed during poor weather conditions.

The instrument can measure stellar motion so precisely that it detects planets with Earth-like mass around distant stars. This capability has enabled researchers to catalog numerous exoplanets and expand our knowledge of planetary systems beyond our own.