Buyer’s guide to telescopes at the best sites:

Future optical/infrared telescopes will need to be much larger than today’s, if they are to address such key challenges as direct observations of Earth-like exoplanets and of the first stars formed after the big bang. In this paper I consider the most promising of the new sites, both on the ground a...

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Bibliographic Details
Main Authors: Dome A, Shackleton Rim, Roger Angel
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
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Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.145.3573
http://caao.as.arizona.edu/publications/2004%20spie%20plenary%20final%202.pdf
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Summary:Future optical/infrared telescopes will need to be much larger than today’s, if they are to address such key challenges as direct observations of Earth-like exoplanets and of the first stars formed after the big bang. In this paper I consider the most promising of the new sites, both on the ground and in space, and telescope concepts to take advantage of their complementary scientific potential. Ground based telescopes with adaptive optics will be capable of diffraction limited imaging, down to a short wavelength limit set by the amplitude and speed of the atmospheric turbulence. The best conditions are on the high Antarctic plateau, where recent measurements at Dome C show turbulence typically half the amplitude of the best temperate sites, with temporal evolution at half the speed 1. Thus uniquely in Antarctica, diffraction limited imaging at optical wavelengths should be practical. Conditions there are also best for infrared astronomy, given the combination of minimal aberration and winter temperatures averaging as low as 200K at Dome A (the highest point). In space, well away from the warm Earth, conditions are even better, with 24 hour/day observing free from all atmospheric aberration, and the potential for passive cooling to 50K or less by use of a sunshield. L2 and the Moon’s south pole are such optimal space locations. A telescope at L2 requires only a little fuel to stay on orbit, and can be accurately pointed despite solar torques by well established active methods based on star trackers, gyros and reaction