10-m Hobby-Eberly Telescope

With its 10-meter mirror, the Hoby-Eberly Telescope (HET) is one of the world's largest optical telescopes. The HET is optimized for spectroscopy, and is ideal for searching for planets around other stars, as well as probing distant galaxies, exploding stars, black holes, and more. The HET is a joint project of The University of Texas at Austin, The Pennsylvania State University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

Telescope Parameters

Optical
Primary Mirror, prime focus
Diameter                                                    10.0 m (433")
Focal length 36.500 m (120')
F-ratio 3.65
Field of view 22 arcmin
Plate scale 5.65 arcsec/mm
Accessible declination* -10.3 to +71.6 deg
Maximum declination** -12.0 to +74.0 deg
Maximum track time 2.8 hours at Dec=+67.2deg

*for tracks passing through primary mirror center at track center
 **for tracks at least 30min long without a fully illuminated pupil at track center

Mechanical
Primary Mirror
Weight                                                          13.5 t (27,000 lbs) (250lb/segment)
Thickness 50 mm (2 inches) at the edge
Material Zerodur
Segments 91 (6 spares)
Segment size Hexagonal, 1m diameter
Shape Spherical
Radius of Curvature 26 m
Telescope 
Weight 153 tons
Bearings
Azimuth axis Pressurized air bearings on concrete pier
Dome
Diameter 26 m (86 ft)
Weight 20 t (22 tons)
Fixed Elevation Telescope
Elevation Angle 55 degrees
Angular range of tracker on sphere 12 degrees

 

Historical
Initial Construction
Started                                                        1994                                                           
First light Dec 1996           
Dedication Oct 1997
End of commissioning Oct 1999
Wide Field Upgrade
HET taken offline Sep 2013
Upgrade first light Jul 2015
Early science operations Jul 2016
Full science operations Jun 2018

 

Instruments

All at Prime Focus (f/3.65):

Future Instruments 

Observer Information 

Reference paper for the HET's Wide Field Upgrade Hill, et al 2021 AJ, 162, 298