Planned outage -- MAST Services will be unavailable Tuesday 16 January 2018, 09:00 to 17:00 EST (14:00 to 22:00 GMT) for system upgrades. We apologize for the inconvenience.
HUT Mirror Description
Caption: This photo shows the HUT primary mirror as it appeared prior to
Astro-2. The mirror had just been coated with a material called silicon
carbide (SiC), which improved its ultraviolet reflectivity by a factor
of two. (Click on the above photo to see a larger version.)
The HUT primary mirror, seen here in a lab photo during the construction
of the telescope, is 0.9-m (36 inches) in diameter and is made of CERVIT
(a ceramic-based material with very good thermal properties).
For Astro-1, the mirror was coated with a
thin layer of the element iridium, which was the best material available
for reflecting far and extreme ultraviolet light at that time. For
Astro-2, the mirror was recoated with a new material, silicon carbide,
which has about a factor of two better reflectivity over the HUT primary
wavelength range (840 - 1840 Angstroms). This permitted HUT to see
fainter objects during Astro-2 and get higher quality data on bright
Caption: The mirror cell surrounds the mirror in this photo, and the
three-legged mirror support is in place. This photo was taken just
prior to inserting the mirror assembly into the telescope tube.
(Click on the above photo to see a larger version.)