News & Updates

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




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



The apparent shift in position of an object relative to background objects when observed from two different locations. An everyday demonstration of parallax is easy to try: hold a finger in front of your face, and without moving it, wink one eye and then the other. When you see the position of your finger change with respect to the background, you are seeing parallax. Astronomers measure the parallax of a stars close to the Earth using Earth's orbital diameter as a baseline. The astronomer observes a star at six-month intervals, when Earth on opposite sides of the Sun. Astronomers look for a shift in the position of the star, and if they find one, they can use simple geometry to measure the star's distance from Earth.

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