Country’s first & largest ‘MAST’ telescope functional at Udaipur Solar Observatory
Udaipur : Udaipur Solar Observatory, one among the 6 GONG (Global Oscillations Network Group) sites in the world, has now the country’s first and largest Telescope to observe the Sun. After China, Udaipur is second in the world to have the unique telescope Multi Application Solar Telescope (MAST) for the detailed study of the solar activity including its magnetic field. Unlike other telescopes, 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 the future’ said Prof U.R Rao, a space scientist and chairman of the Governing Council of the Physical Research Laboratory (PRL), Ahmedabad at the dedication ceremony organized here on Tuesday. ISRO Chairman A.S. Kiran Kumar who couldn’t make it for the event, sent his message to fellow scientists, congratulating them for the major achievement. The observatory, situated in an island in the middle of lake Fatehsagar, is a part of the PRL, an autonomous unit of the Department of Space.
The observatory’s strategic location, with large water body surrounding the telescopes decrease the amount of heating of the surface layers. This decreases the turbulence in the air mass and thereby improves the image quality and seeing. The main objective of obtaining the high spatial and temporal resolution observations of solar photosperic and chromospheric activity is to understand the various dynamic phenomena occurring on the Sun’s surface, Prof Rao said.
The scientists here had many important results earlier using data from other sources. But these look at only one layer of the solar atmosphere. Using MAST, they plan to extend the studies to other layers using multiple spectral line diagnostics. In this way they would get a 3-D picture of the phenomena. The observatory team lead by Prof P. Venkatakrishnan, plan to cooperate with GREGOR 1.5m and BBSO 1.6m telescopes operating elsewhere in the world by extending longitude coverage. “ We plan to provide a long-time data base to obtain lasting contributions from MAST on outstanding solar cycle related problems like behaviour of magnetic stresses as a function of the epoch of the solar cycle” Prof Venkatakrishnan said. ‘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..
MAST is an off-axis Gregorian-Coude telescope with a 50 cm aperture and itsdome is a collapsible dome made of tensile fabric. Scientists had proposed for MAST in 2004 and preparations had been going on since for its installations. Built by Mechanical and Optical Systems (AMOS) of Belgium, MAST was tested by USO for onsite acceptance. The back-end instruments of MAST, developed in-house at USO, include an adaptive optics system and a narrow band imaging polarimeter using a tandem Fabry-Perot etalon pair and LCVR polarimetric module. Another instrument, viz., a spectropolarimeter, has been developed at ISRO Satellite Centre. Test results accumulated over a year was examined by a committee of experts and telescope has now been made operationalized after 11 years.
Strategic location of the 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 that were used to store water collected during the monsoon. This water supply could last during several years of 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. A milestone was added in the USO’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 each minute.