OPN Image Galleries



Image of the Week



After Image



Photo Contests

Guide star

Optics and Photonics Image of the Week RSSRSS
Guide star

Guide star

A powerful laser at the Allgäu Public Observatory in Ottobeuren, Germany, creates an artificial “guide star” (used in correcting for atmospheric blurring in telescope observations) by causing sodium atoms in the atmosphere, 90 km above, to glow. — ESO/T. Kasper (AVSO)

> Download hi-res image