AMBER (Very Large Telescope)

AMBER stands for Astronomical Multi-Beam Recombiner. It was a near-infrared astronomical interferometer installed at the Very Large Telescope (VLT) Interferometer (VLTI) on Cerro Paranal in Chile. Developed by a consortium of European institutions, AMBER combined the light from up to three telescopes of the VLTI, either the 8.2-meter Unit Telescopes (UTs) or the 1.8-meter Auxiliary Telescopes (ATs). This coherent combination allowed astronomers to achieve an angular resolution equivalent to that of a telescope with a diameter equal to the separation between the contributing telescopes, effectively creating a "virtual telescope" of much larger size.

The primary scientific goal of AMBER was to study the inner regions of young stellar objects, the environments of hot stars, and the nuclei of active galactic nuclei (AGN). By providing high-resolution observations in the near-infrared, AMBER enabled detailed investigations of the structure, kinematics, and physical conditions of these objects. It was particularly useful for probing the innermost regions of protoplanetary disks around young stars, helping to understand the formation of planets.

AMBER operated from 2004 until 2018, when it was decommissioned. During its operational lifetime, it contributed significantly to the field of high-resolution astronomy and provided valuable insights into the formation and evolution of stars and galaxies. Data obtained by AMBER continues to be analyzed and used in astronomical research. Although no longer operational, its legacy is carried on by other interferometric instruments on the VLTI and other observatories.