Vacuum Tower Solar Telescope
Encyclopedia
The Richard B. Dunn Solar Telescope is a unique vertical-axis solar telescope
, located at the National Solar Observatory
at Sacramento Peak, New Mexico
. The optical path starts at a heliostat
on top of a 136 feet (41.5 m) tower and continues 193 feet (58.8 m) more underground to the primary mirror. It then returns to one of six quartz optical windows in the floor of an optical laboratory at ground level. The optics are evacuated to eliminate distortion due to convection
in the telescope that would otherwise be caused by the great heat produced by focusing the light of the sun
.
A unique feature of the telescope is its approach to image derotation: the entire 100 metres (328.1 ft) telescope and 40 feet (12.2 m) optics lab, 250 tons total, rotates suspended from a mercury float bearing at the top of the tower.
Originally the Vacuum Tower Telescope at Sacramento Peak, it was renamed in 1998http://www.noao.edu/outreach/press/9807.html in honor of the retiring solar astronomer Richard B. Dunn who was the driving force behind its construction.http://dot.astro.uu.nl/rjr-publications/1999sunspot-dot.pdf The lowest excavated point (the bottom of the sump) is 228 feet (69.5 m) below ground.
Solar telescope
A solar telescope is a special purpose telescope used to observe the Sun. Solar telescopes usually detect light with wavelengths in, or not far outside, the visible spectrum.-Professional solar telescopes:...
, located at the National Solar Observatory
National Solar Observatory
The mission of the National Solar Observatory is to advance knowledge of the Sun, both as an astronomical object and as the dominant external influence on Earth, by providing forefront observational opportunities to the research community...
at Sacramento Peak, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
. The optical path starts at a heliostat
Heliostat
A heliostat is a device that includes a mirror, usually a plane mirror, which turns so as to keep reflecting sunlight toward a predetermined target, compensating for the sun's apparent motions in the sky. The target may be a physical object, distant from the heliostat, or a direction in space...
on top of a 136 feet (41.5 m) tower and continues 193 feet (58.8 m) more underground to the primary mirror. It then returns to one of six quartz optical windows in the floor of an optical laboratory at ground level. The optics are evacuated to eliminate distortion due to convection
Convection
Convection is the movement of molecules within fluids and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids....
in the telescope that would otherwise be caused by the great heat produced by focusing the light of the sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
.
A unique feature of the telescope is its approach to image derotation: the entire 100 metres (328.1 ft) telescope and 40 feet (12.2 m) optics lab, 250 tons total, rotates suspended from a mercury float bearing at the top of the tower.
Originally the Vacuum Tower Telescope at Sacramento Peak, it was renamed in 1998http://www.noao.edu/outreach/press/9807.html in honor of the retiring solar astronomer Richard B. Dunn who was the driving force behind its construction.http://dot.astro.uu.nl/rjr-publications/1999sunspot-dot.pdf The lowest excavated point (the bottom of the sump) is 228 feet (69.5 m) below ground.