A Unique Liquid-Mirror Telescope sees first light in the Indian Himalayas

Context

India has commissioned a unique liquid-mirror telescope atop a mountain in the Himalayan region that will keep a watch on the skies to identify transient or variable objects.

About

About International Liquid-Mirror Telescope (ILMT):

The telescope, commissioned at Devasthal, a hill in Uttarakhand.
It is located at an altitude of 2450 metres at the Devasthal Observatory campus of Aryabhatta Research Institute of Observational Sciences (ARIES).
ARIES is an autonomous institute under the Department of Science and Technology (DST), Govt. of India in Nainital district, Uttarakhand.
It is the first liquid mirror telescope in the country and the largest in Asia.
It will help in surveying the sky making it possible to observe several galaxies and other astronomical sources just by staring at the strip of sky that passes overhead.
The unique telescope will monitor the sky for transitory or variable objects such as supernovae, gravitational lenses, space debris, and asteroids.
It is built by astronomers from India, Belgium and Canada.
The novel instrument employs a 4-meter-diameter rotating mirror made up of a thin film of liquid mercury to collect and focus light.
The telescope was designed and built at the Advanced Mechanical and Optical Systems Corporation and the Centre Spatial de Liege, Belgium.
The major instrumentation funding was jointly provided by Canada and Belgium while India will be responsible for the operations and upkeep of the telescope.
The ILMT will operate every night for five years and carry out daily imaging except between June and August monsoon months, a precaution to protect the instruments from humid conditions.

How it works?

The scientists from the three countries spun a pool of mercury which is a reflective liquid, so that the surface curved into a parabolic shape which is ideal for focusing light.
A thin transparent film of mylar protects the mercury from wind.
The reflected light passes through a sophisticated multi-lens optical corrector that produces sharp images over a wide field of view.
A large-format electronic camera located at the focus records the images.
The technology of liquid mirror (LM) telescope is relatively simple. ?Three components ?are required:
- ?A ?dish ?containing ?a ?reflecting ?liquid ?metal ?(essentially ?mercury),
- ?An ?air ?bearing ?on which ?the ?LM ?sits, and
- ?A drive system.

What is Mylar?

Mylar, also known as BoPET (Biaxially-oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET).
It is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties, and electrical insulation.