Astrosat Current Affairs - 2019
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India’s first dedicated space observatory AstroSat along with other space and earth-based observatories have detected a massive coronal explosion on Proxima Centauri, sun’s closest star neighbour.
The explosion was detected as part of joint multi-wavelength simultaneous observational campaign undertaken by three space-based observatories, Astrosat, Chandra and Hubble Space Telescope and the ground-based High Accuracy Radial velocity Planet Searcher (HARPS) observatory.
It is group of stars which hosts an Earth-like habitable planet — Proxima Centaur b — orbiting within (Proxima Centauri) its habitable zone. It is a cool dwarf star located around 4.25 light years away from the Earth. It was discovered in 2016.
The massive coronal explosion has sent out powerful solar flare having energy of 10-raised-to-30 ergs, about 100 times a typical solar flare. Such powerful flaring may have produced large radiations and particles which may significantly influence the atmosphere of the Proxima Centauri b and affect its habitability.
The habitability of Proxima Centauri especially its ability to sustain its atmosphere and in particular to sustain water in liquid form may get affected due to abnormal planetary atmosphere heating due absorption of the high-energy photons like the ultraviolet (UV) and X-ray photons released by the coronal explosion.
If such a massive flare occurs in our Sun, it might have a devastating effect on power grids, interrupt broadcasts and electricity, affect electronic instruments, and cause excess UV radiation in space.
Coronal explosion: is an unusually large release of plasma and magnetic field from the solar corona. They often follow solar flares and are normally present during a solar prominence eruption. The plasma is released into the solar wind, and can be observed in coronagraph imagery.
India’s first dedicated space observatory, ASTROSAT has captured the rare phenomenon of a small six-billion-year-old vampire star preying on a bigger celestial body.
The vampire star phenomenon is observed when smaller star sucks material (mass and energy) out of the bigger companion star, causing its eventual death.
It is also called a blue straggler as small star becomes bigger, hotter and bluer, giving it the appearance of being young, while the ageing companion burns out and collapses to a stellar remnant.
- Astrosat is India’s first dedicated multi-wavelength space observatory launched in September 2015. It is one of the major scientific missions of ISRO after the highly acclaimed Chandrayaan-I and Mangalyaan.
- It is placed at low earth equatorial orbit at altitude of 650 km. It has ability to observe celestial bodies like cosmic X-Ray sources and distant stars in different wavelengths simultaneously.
- It can observe the universe through ultraviolet, optical, low and high energy X-ray components of the electromagnetic spectrum. It has mission life of 5 years.
- Its successful launch made India member of select elite group of nations comprising US, Japan, Russia and Europe having its own space observatory.