News & Updates

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

7 October 2013
VIRUS Units Come Together

9 September 2013
Last Look at Sky Before Upgrade

10 May 2013
Mirror Coating Smooths the Way for HET Upgrade

 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




H.E.T. PFIP Removal - Play video



A unit of distance equal to 3.26 light-years. The name means "PARallax-SECond," and it refers to a way to measure the distances to other stars. The most accurate way to measure the distances to close stars is to use basic geometry. Astronomers measure the position of a star in the sky at six-month intervals, when Earth is on opposite sides of the Sun. If the star is close, then it will appear to shift a bit compared to the background stars. It's the same effect you see if you hold your finger in front of your face and look at it with first one eye, then the other: the finger appears to move against the background of objects. This effect is called parallax. If a star has a parallax of one second -- in other words, it appears to shift back and forth across the sky by exactly one second of arc (1/3600 of a degree), then its distance is one parsec.

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