The photometric telescope

The domed building encloses the 0.5-meter Photometric Telescope used for monitoring subtle changes in the atmosphere during the course of the survey. Its principal function is to aid astronomers in accurately calibrating an object's brightness, as measured with the main telescope. The other dome in the distance houses the 1.0-meter New Mexico State University remote observing telescope.

A photo of the 0.5-meter telescope from inside its protective dome. This telescope, like many others, rotates in declination (the "latitude" direction) and right ascension (the "longitude" direction).

A view of the photometric telescope's dome as twilight falls upon Apache Point Observatory.