Hobby Eberly Telescope
The Hobby Eberly Telescope ( HET ) is a new type of reflector telescope optimized for spectroscopy with an effective primary mirror diameter of around 9 m. It is located at 2026 m on Mount Fowlkes in Texas near the McDonald Observatory .
The HET has been designed in a completely new way for optical telescopes . A light gathering power comparable to that of the largest existing telescopes such as the Keck telescopes or the VLT should be achieved at a cost reduced to one fifth - 13.5 million US dollars. Unlike these telescopes, the HET cannot be steered in two directions ( azimuth and height ). It always points to the same height of 55 ° above the horizon, but can be moved azimuthally. This means that only one circle in the sky is accessible at a given time, but over longer periods of time a large part of the sky passes over this circle. The actual tracking of the object to be observed is carried out by a movable tracker near the focal point of the main mirror, while the object moves over this circle. The telescope stands still during this time. Depending on the declination of the object, tracking is possible for a maximum of 0.75 to 2.5 hours.
The spherical main mirror of the Hobby Eberly telescope consists of 91 hexagonal segments, each 1 m in diameter. The size of the main mirror is 11.1 × 9.8 m, the light intensity corresponds to a mirror 9.2 m in diameter. Due to its construction, the HET cannot compete with other large telescopes in terms of flexibility, field of view and spatial resolution, but it should achieve the light-gathering power required for high-resolution spectroscopy particularly cheaply. The first observations with a few segments began in 1996, and scientific operations began in 1999. An improved tracker installed from 2011 enables a field of view of 22 'to be achieved.
The HET is a joint project of the University of Texas at Austin , Pennsylvania State University , Stanford University , Ludwig Maximilians University Munich and Georg August University Göttingen .
The Southern African Large Telescope (SALT) in South Africa is also based on the concept of the Hobby Eberly telescope and has been in scientific use since November 2005.
Web links
- HET page (English)
Individual evidence
Coordinates: 30 ° 40 ′ 51 ″ N , 104 ° 0 ′ 54 ″ W.