About the PRL Mount Abu Observatory at Gurushikhar, Mount Abu

The idea of setting up an optical observatory and initiating the infrared and optical astronomy programme was put forth by PRL during the 1970s. After a suitable astronomical site survey of several locations, Gurushikhar, the highest peak of Aravali range in Mt Abu, Rajasthan (India), was found most appropriate due to its low water vapour, more than 220 observable nights with reasonably good seeing and the site's vicinity to PRL, Ahmedabad (240 kms). The first Telescope that came up at the sight is the 1.2m Telescope.

The construction work for the 1.2m Telescope Observatory Building started around the year 1986. The responsibility of developing the site, including the construction of the access road, telescope building and other facilities, telescope mount and dome, etc., was given to ISRO. The whole observatory was designed and developed indigenously. The design of telescope drives, mount and other support systems, including telescope control, was taken up by the SHAR Centre which also supervised the fabrication work at Chennai. The Telescope 1.2m primary mirror blank came from University of Arizona, US (It was donated by Late Prof. Tom Gehrels), and the Mirror blank was polished in United Kingdom. All the back-end instruments, one of the most important components of the astronomical observations, were developed in parallel with the setting up of the observatory. It may be worth noting that some of those initial instruments are still functioning and competing with new generation instruments. The “first Light” image of star alpha Arietis was acquired with the 1.2 m telescope on November 19, 1994 establishing excellent quality of its optics. The observatory started regular operation immediately with the lunar occultation study of IRC-10557 (v Aquarii) on December 7, 1994. Over the years, it has catered to the observational requirements of the scientific programs of the Astronomy and Astrophysics faculty.

The research programs currently cover a wide range of objects and events, such as studies of solar system objects, search and characteristics of exoplanets, topics in stellar astrophysics like star formation, stellar structure and evolution, Novae and binary systems, supernovae, and starburst and active galactic nuclei. The techniques used are imaging photometry, spectroscopy and polarimetry.

Subsequently due to demand of continous photometric observations of transiant astrophysical phenomena like Novae, GRBs, Cometary Studies etc., it was decided to have a small automated 50cm Telescope to observe such sources using CCDs. Hence ATVS 50cm was concieved around 2011. Further more to do follow-up transit observations of exoplanets, it was decided to have a 43cm Telescope with a large field of view. The 43cm Telescope became active since January 2019.

PRL is also in the process of acquiring a larger fully automated state of the art equipped with primary mirror active optics and secondary mirror on hexapod, a 2.5m aperture telescope. This will give a big boost to the scientific programmes in the Astronomy Division of PRL. The telescope is likely to see it's first light in early 2022. The first light backend instruments will be a 10x10 sq. arcminute FOV CCD Imager with SDSS Filter sets, and PARAS-2 (an advanced version of PARAS) at a resolution of 100,000 under stabalized environment of temperature and pressure controlled to detect and study exoplanets. In the near future we will have many other backend instruments for the 2.5m telescope like low-resolution spectrograph and medium resolution echelle spectroscopy and polarimetry in the optical & near-infrared wavelengths.

All Telescopes belongs to Physical Research Laboratory and are fully funded by Department of Space, Govt. of India.


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Mount Abu Observatory, Near Gurushikhar, Mt. Abu-307501, (Rajasthan) India
Coordinates : 24°39′17.34″N 72°46′45.18″E
Altitude : 1,680 m (5,510 ft)

Mount Abu Observatory Base Office, Observer Transit House, Residential Campus:
Hillview, Gora Chapara, Mt. Abu 307501, (Rajasthan), India
Phones: +91-02974-235229 Fax No: +91-02974-238276