India has set up the country’s first liquid mirror telescope which will identify transient and variable objects such as supernovae, gravitational lenses, space junk and asteroids. The telescope, which is the largest in Asia, was installed at Devasthal, a hill in Uttarakhand.
The observatory was built at an altitude of 2450 meters on the Devasthal Observatory campus of the Aryabhatta Research Institute of Observational Sciences (ARIES). “ILMT is the first liquid mirror telescope designed exclusively for astronomical observations installed at ARIES’ Devasthal Observatory,” said Professor Dipankar Banerjee, Director of ARIES.
The telescope will aid in the study of the sky, making it possible to observe several galaxies and other astronomical sources simply by looking at the band of sky passing overhead. The observatory was developed by Indian, Belgian and Canadian scientists and uses a rotating mirror 4 meters in diameter made of a thin film of liquid mercury to collect and focus light.
The scientists rotated a pool of mercury, which is a reflective liquid, so that the surface curved into a parabolic shape ideal for focusing the light. A thin transparent film of mylar protects the mercury from the wind. Reflected light passes through a sophisticated multi-lens optical corrector that produces sharp images over a wide field of view.
A color composite photograph of a small portion of the sky observed with the ILMT through the g, r, and i Sloan filters. The galaxy NGC 4274 is visible in the upper right corner. (Photo: ILMT)
During this time, a large format electronic camera located in the foyer records the images.
Professor Paul Hickson (University of British Columbia, Canada), an expert in liquid mirror technology, said that “the rotation of the Earth causes the images to drift through the camera, but this movement is electronically compensated by the camera. This mode of operation increases observation efficiency and makes the telescope particularly sensitive to faint and diffuse objects.
The Devasthal Observatory now hosts two four-meter class telescopes, the ILMT and the Devasthal Optical Telescope (DOT). Both are the largest aperture telescopes available in the country. Professor Dipankar Banerjee is excited about the application of Big Data and Artificial Intelligence/Machine Learning (AI/ML) algorithms that will be implemented to classify objects observed with ILMT.
“The wealth of data generated by the ILMT survey will be exemplary. In the future, several young researchers will work on different scientific programs using the data from ILMT,” said Dr. Kuntal Misra, who is the project researcher of ILMT. Regular data will begin later this year, ILMT will be producing approximately 10 GB of data each night, which will be rapidly analyzed to reveal variable and transient stellar sources.