News & Updates

5 November 2015
Upgraded Hobby-Eberly Telescope Sees First Light

28 June 2015
Sophisticated set of mirrors will sharpen, widen HET’s view of the sky

31 March 2015
Engineers install, test cryogenic system

17 March 2014
Tracking HET’s Progress

 Dark energy is not only terribly important for astronomy, it's the central problem for physics. It's been the bone in our throat for a long time.”

Steven Weinberg
Nobel Laureate
University of Texas at Austin




A video introduction to dark energy, narrated by StarDate's Sandy Wood - Play video


Doppler shift

A change in wavelength caused by an object's motion toward or away from the observer. An everyday example is the change in pitch of a siren or train whistle. When it moves toward you, the sound waves are compressed, so the pitch rises; when it moves away from you, the sound waves are stretched, so the pitch falls. The same thing happens with visible light and other forms of electromagnetic radiation. If a star or galaxy is moving away from us, its light is shifted to redder wavelengths; if it is moving toward us, its light is shifted to bluer wavelengths. Astronomers can use this shift to calculate the object's speed, and, with additional observations, to deduce its distance.

Media Gallery

Gary Hill and VIRUS

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