India’s first ever multi-wavelength astronomical observatory AstroSat completed five years of operations this week, marking a successful run of imaging celestial objects in space. In its tenure, the observatory by ISRO has managed to make 1,166 observations of 800 unique celestial sources to date, proposed by scientists from both India and abroad.
For those unaware, AstroSat was launched by the Indian Space Research Organisation on September 28, 2015, aboard the PSLV-C30 from Satish Dhawan Space Centre, Sriharikota. Serving as the first dedicated Indian astronomy mission. The AstroSat was built to study celestial sources in X-ray, optical and UV spectral bands simultaneously.
This was to be achieved through a total of five payloads on board AstroSat, amounting to a lift-off mass of 1515 kg. The scientific data gained by the five payloads of AstroSat is then telemetered to the ground station at Mission Operations Complex (MOX) of ISRO Telemetry, Tracking and Command Network (ISTRAC), Bengaluru.
Interestingly, this simultaneous multi-wavelength observation of various astronomical objects is made possible through a single satellite. AstroSat currently serves in a 650 km orbit inclined at an angle of 6 degree to the equator.
In its five years of operation, AstroSat has explored numerous stars and star clusters. In addition, it has mapped large and small satellite galaxies of the Milky Way called ‘Magellanic Clouds’. The five years of action is supposed to be the “minimum useful life” of the AstroSat mission as per ISRO.
A statement by the Department of Science and Technology (DST) marking the occasion said, “Its superior spatial resolution capability has enabled astronomers to probe star formation in galaxies as well as resolve the cores of star clusters (three times better than the last NASA mission, GALEX).”
The highlight among the equipment on board AstroSat is the Ultra-Violet Imaging Telescope (UVIT), a 3-in-1 imaging telescope simultaneously observing the visible, the near-ultraviolet (NUV), and the far-ultraviolet (FUV) spectrum. This is done through two separate telescopes, one of which works in the visible (320-550 nm) and the NUV (200-300 nm) range while the other works only in the FUV (130-180 nm). The complete equipment weighs a total of of 230 kilograms.
Thanks to UVIT, AstroSat was most recently able to identify extreme-UV light from a galaxy far far away. The newfound galaxy is located 9.3 billion light-years away from Earth, so far that its UV emissions even escaped detection from NASA’s Hubble Space Telescope earlier.
(With inputs from PTI)