C. Donald Shane Telescope

The C. Donald Shane Telescope is a research instrument on Mount Hamilton with a primary mirror measuring 120 inches in diameter and three focal stations for different types of astronomical observation. The facility houses specialized instruments including the Kast Double Spectrograph that enable detailed analysis of celestial objects.

Operations began in 1959 when it ranked as the world's second-largest optical telescope. The mirror was originally intended for a different project before being adapted for this instrument.

The telescope serves as a learning center where University of California students gain practical experience in observing the night sky and analyzing astronomical data. Visitors can witness how researchers work here and train the next generation of astronomers.

The facility is located at high elevation on a mountain, so visitors should allow time to acclimate to thinner air conditions. Visit on clear nights when atmospheric conditions are best for observations and viewing opportunities.

The instrument uses a laser system visible from the ground that is part of an advanced program to improve image quality. This adaptive optics system helps correct for atmospheric distortions and enables sharper observations.