Kueyen

Kueyen is the second Unit Telescope (UT2) of the European Southern Observatory’s Very Large Telescope (VLT) array, located at the Paranal Observatory in northern Chile. Each Unit Telescope in the VLT is an 8.2-meter-class telescope that can operate independently or in combination with the other UTs and with the Very Large Telescope Interferometer (VLTI) to achieve higher angular resolution through interferometry. Kueyen has played a central role in a broad range of astronomical programs, including high-resolution imaging, spectroscopy, and interferometric observations.

Name and origin: The telescope’s name, Kueyen, comes from the Mapuche language of Chile and is associated with the Moon. It is part of ESO’s naming scheme for the VLT UTs, which also includes Antu (Sun), Melipal, and Yepun (Venus).

Technical role: As UT2, Kueyen provides a large light-gathering aperture for deep imaging and spectroscopic studies and is equipped with the VLT’s suite of optical and near-infrared instruments and adaptive optics systems. In VLTI operations, Kueyen can be used together with the other UTs or with auxiliary telescopes to form long-baseline interferometric arrays, enabling measurements with very high angular resolution.

Overview: The VLT, including Kueyen, represents a major component of ESO’s capability to observe the optical and near-infrared sky from the Atacama Desert. Its observations contribute to research on exoplanets, distant galaxies, star formation, and the dynamics of celestial objects.