Udaipur Now Has The Country's Largest Solar Telescope!

The Udaipur Solar Observatory (USO), one of the six GONG (Global Oscillations Network Group) sites in the world, has now the country's largest telescope to observe the sun.

After China, Udaipur is second in the world to have the unique multi-application solar telescope (MAST) for the detailed study of the solar activities. Unlike other telescopes, the MAST is capable of capturing three dimensional aspects of the solar magnetic fields, further enabling the scientists to get a better understanding of the solar flares and eruptions taking place in such twisted magnetic fields. "This could facilitate space weather predictions in future," said professor UR Rao, a space scientist and chairman of the governing council of Physical Research Laboratory (PRL), Ahmedabad, at the dedication ceremony organised here on Tuesday.

ISRO chairman AS Kiran Kumar, who couldn't make it to the event, sent his message to fellow scientists, congratulating them for the major achievement. The observatory, situated on an island in the middle of Fatehsagar lake, is a part of the PRL, an autonomous unit of the department of space.

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What is the objective

The observatory's strategic location, with a large water body surrounding the telescope, decreases the amount of heating of the surface layers. This reduces the turbulence in the air mass and thereby improves the image quality. The main objective of obtaining the high spatial and temporal resolution observations of solar photospheric and chromospheric activity is to understand the various dynamic phenomena occurring on the sun's surface, Rao said.

Udaipur Times

The scientists here had got many important results earlier using data from other sources. But those were looking at only one layer of the solar atmosphere. Using the MAST, they plan to extend the studies to other layers using multiple spectral line diagnostics. In this way, they would get 3D pictures of the phenomena.

The observatory team, led by professor P Venkatakrishnan, plans to cooperate with GREGOR 1.5 m and BBSO 1.6 m telescopes operating elsewhere in the world by extending longitude coverage. "We plan to provide a long-time database to obtain lasting contributions from the MAST on solar cycle-related problems like behaviour of magnetic stresses as a function of the epoch of the solar cycle," said Venkatakrishnan. "We aim to combine the techniques of helioseismology with magnetic field measurements to link the processes underneath the active regions to the processes happening in the solar corona," he said.

What is MAST

The MAST is an off-axis Gregorian-Coude telescope with a 50 cm aperture and its dome is a collapsible one made of tensile fabric. The scientists had proposed for MAST in 2004 and preparations had been going on since for its installation. Built by the Advanced Mechanical and Optical Systems (AMOS) of Belgium, the MAST was tested by Udaipur Solar Observatory for onsite acceptance.

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The back-end instruments of MAST, developed in-house at USO, include an adaptive optics system and a narrow band imaging polarimeter. The test results accumulated over a year were examined by a committee of experts and the telescope has now been made operational after 11 years.

Strategic location of USO

In most places, lakes are associated with abundant rainfall. However in Udaipur, the wisdom of the administrative bodies 500 years ago resulted in a system of lakes which were used to store water collected during the monsoon. This water supply could last for several years during lean monsoons. Because the rains were scanty in general, Udaipur site can boast of more than 250 days of continuous sunshine which allows to observe the sun properly during the day.

Udaipur Times

A milestone was added in the Udaipur Satellite Observatory's history in October 1995 when it appeared on the world map after being included in the GONG project. The other sites selected under GONG are the Canary Islands in Spain, CTIO in Chile, Hawaii and Big Bear in USA and Learmonth in Australia. A sophisticated 1.5 million dollar, state-of-the-art instrument was installed in Udaipur under the project which monitors the sun automatically and takes digital velocity images of it every minute.

(Originally published in The Times of India)