The Laser Guide Star at Paranal Observatory

© Stéphane Guisard "Los Cielos de Chile"

The images below are tripod astrophotos taken with a Canon 20Da  camera and a wide field lens. They were taken at Paranal Observatory,
located in the Atacama desert, North of Chile.
The yellow Laser beam visible on the images is generated in one of the dome by a small (50cm diameter) dedicated telescope and sent to the high atmosphere to produce, at an altitude of ~90 km, an artificial star. This star is then used by the main telescope (8m diameter mirror) Adaptive Optics system to measure and correct in real time the distorsions that the atmosphere produces on the images.

The image below shows the Laser Beam launched from UT4 dome. The dome on the right is housing the VST  (VLT Survey Telescope, 2.5m diameter). The Large and small Magellanic clouds are also visible on the top left of the Laser.

The Laser Guide Star beam launched from UT4, the dome on the left is the one of UT2.
The beam seems to cross Orion nebula, in Orion constellation just in the middle of the  image. The bright star is Sirius.

The Laser Guide Star beam launched from UT4. The other domes are respectively, from left to right : UT2, UT3 and a bit of the VST dome is also visible. Orion constellation is clearly visible as well as the Pleiades
(small star cluster just above UT2 dome).