Laser Guide Star at VLT to shine brighter light on stars
It appears suddenly over the southern hemisphere, a new neighbour in the crowded black sky.
But this "star" is not a real one.
Created by a powerful laser beam, it can be made to shine to order by the astronomers at the Paranal Observatory in Chile's Atacama Desert.
"We call it a Laser Guide Star, or LGS, and it is an artificial star that we create by illuminating the sodium layer of the atmosphere," explains Frederic Gonte, head of instrumentation at Paranal.