First light

The first light is the moment when a telescope is first used to take an astronomical image after its construction. Sometimes the term refers to the first image of a new instrument.

Typically, the first light image is of no scientific interest and has a very poor quality, since the various telescope elements must be adjusted for optimum efficiency. Usually, an important and spectacular celestial object is chosen.

Despite this, a first light is always a moment of great excitement, both for the people who designed and built the telescope, and for the astronomical community.