Analysis of information sources in references of the Wikipedia article "Guide star" in English language version.
GALACSI will rely on 4 sodium lasers launched from the centre piece of one of the Unit Telescopes of the VLT to produce "artificial stars", known as guide stars. Sensors then follow the motion of these guide stars as the light from them flickers in the turbulent atmosphere. That allows a computer to calculate the correction that must be applied to the telescope's deformable secondary mirror (itself a new addition to the VLT) to compensate for the atmospheric disturbance. In this way, extremely sharp images of the real celestial objects can be obtained.
The dye laser, similar to that pioneered at Livermore for its Atomic Vapor Laser Isotope Separation program, creates a glowing star of sodium atoms measuring less than 1 meter in diameter at an altitude of about 100 kilometers above Earth's surface. This artificial reference can be created as close to the astronomical target as desired so that the light from the laser star and the observed object pass through the same small part of the atmosphere.
GALACSI will rely on 4 sodium lasers launched from the centre piece of one of the Unit Telescopes of the VLT to produce "artificial stars", known as guide stars. Sensors then follow the motion of these guide stars as the light from them flickers in the turbulent atmosphere. That allows a computer to calculate the correction that must be applied to the telescope's deformable secondary mirror (itself a new addition to the VLT) to compensate for the atmospheric disturbance. In this way, extremely sharp images of the real celestial objects can be obtained.
The dye laser, similar to that pioneered at Livermore for its Atomic Vapor Laser Isotope Separation program, creates a glowing star of sodium atoms measuring less than 1 meter in diameter at an altitude of about 100 kilometers above Earth's surface. This artificial reference can be created as close to the astronomical target as desired so that the light from the laser star and the observed object pass through the same small part of the atmosphere.
