Hobby–Eberly Telescope

The Hobby - Eberly Telescope ( HET ) is a novel optimized for spectroscopy reflecting telescope with an effective primary mirror diameter of about 9 m. Its location is at 1980 m altitude on Mount Fowlkes in Texas near the McDonald Observatory.

The HET is designed to optical telescopes completely new way. A light gathering power comparable to the largest existing telescopes such as the Keck telescopes and the VLT should be achieved with dramatically reduced cost. Other than these telescopes the HET ( azimuth and elevation ) is not executed in two directions. It always points in the same amount of 55 ° above the horizon, but is movable in azimuth. At any given time so that only one circuit in the sky accessible over long periods, but sweeps over a large part of the sky that circuit. The actual tracking of the object to be observed is provided by a mobile tracker near the focus of the primary mirror while the object moving across the circle. The telescope stands still during this time. Depending on the declination of the object tracking up to more than 0.75 to 2.5 hours is possible.

The spherical primary mirror of the Hobby - Eberly telescope consists of 91 hexagonal segments, each 1 m in diameter. The size of the primary mirror is 11.1 × 9.8 m, the light collecting effect is that of a mirror of 9.2 m diameter. Due to its construction, the HET can not compete in flexibility, visual field and spatial resolution with other large telescopes, but is the necessary for high-resolution spectroscopy of light -gathering capability to achieve especially favorable. Through a tracker installed in 2011, improved a field of view is achieved by 22 arcminutes.

The HET is a joint project of the University of Texas at Austin, Pennsylvania State University, Stanford University, Ludwig- Maximilians- Universität München, and Georg -August-Universität Göttingen. First observations with few segments started in 1996, 1999, the scientific operations began.

Also, the Southern African Large Telescope SALT in South Africa is based on the concept of amateur Eberly telescope and is since November 2005 for scientific operations.