World's First Liquid Mirror Telescope Goes Live
Posted: Wed Jun 29, 2022 10:10 pm
India has built the world's first operational Liquid Mirror Telescope, high up in the Himalayan mountains. The International Liquid Mirror Telescope (ILMT) is a 4-meter class telescope (156" diameter primary) that was constructed at 8,000 ft elevation on the campus of Devasthal Observatory, which is owned by the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital in Uttarakhand (in Northern India).
Instead of using glass or mirrors to collect the light, this telescope uses a layer of liquid mercury that floats on a thin layer of compressed air. This liquid mercury (quicksilver) is then spun, creating a very precise parabolic-shaped mirror.
Why would you want to use a liquid instead of pre-forming a mirror in the traditional way? The main advantage is cost. Liquid is cheap! This telescope costs about 1/10th that of a nearby standard 3.6 meter telescope.
One downside, though, is that since it is a liquid mirror it can really only be pointed straight up at the zenith. However, the ILMT is an uber fast f/2 configuration, giving it a relatively large 27 arc minute field of view (nearly the same size as a Full Moon).
They plan on using this telescope to conduct quasar and gravitational-lensing observations from its advantageous +29N latitude for the first five years. In its present configuration it can monitor 50 square degrees of sky and reach magnitude +22. And at this location it will have a good view of the region of sky around the North Galactic Pole.
The ILMT went live in April, and first science using the telescope is expected to be done later this year.
https://gizmodo.com/india-liquid-mirror ... 6RaVUo9NuY
ILMT Website: https://www.aries.res.in/facilities/ast ... copes/ilmt
Suresh
Instead of using glass or mirrors to collect the light, this telescope uses a layer of liquid mercury that floats on a thin layer of compressed air. This liquid mercury (quicksilver) is then spun, creating a very precise parabolic-shaped mirror.
Why would you want to use a liquid instead of pre-forming a mirror in the traditional way? The main advantage is cost. Liquid is cheap! This telescope costs about 1/10th that of a nearby standard 3.6 meter telescope.
One downside, though, is that since it is a liquid mirror it can really only be pointed straight up at the zenith. However, the ILMT is an uber fast f/2 configuration, giving it a relatively large 27 arc minute field of view (nearly the same size as a Full Moon).
They plan on using this telescope to conduct quasar and gravitational-lensing observations from its advantageous +29N latitude for the first five years. In its present configuration it can monitor 50 square degrees of sky and reach magnitude +22. And at this location it will have a good view of the region of sky around the North Galactic Pole.
The ILMT went live in April, and first science using the telescope is expected to be done later this year.
https://gizmodo.com/india-liquid-mirror ... 6RaVUo9NuY
ILMT Website: https://www.aries.res.in/facilities/ast ... copes/ilmt
Suresh