INDIA is ready with GROWTH-India telescope’s first science observation

First science observation

The GROWTH-India telescope was commissioned six months ago soon after which it saw first light, on the night of June 12. “The telescope has been taking readings since then, and this is the first ‘follow-up’ work. We are happy to see this first science observation,” said G C Anupama, who Professor-in-Charge of the Indian Astronomical Observatory and is based at Indian Institute of Astrophysics (IIAP), Bengaluru.

The celestial object was first noticed by a different group which saw the nova explosion. “We then pointed our telescope in that direction and measured the brightness. We found that it was fading at the rate expected for such events. This is a small step in astronomy but a big leap for us, because it is the first scientific result obtained by this telescope,” said Varun Bhalerao a faculty member at IIT Bombay and a Principal Investigator of the project along with Professor Anupama.

This recurrent nova, named M31N-2008, has been observed to erupt several times, the most recent eruption happening in November 2018. Recurrent nova systems are interesting because they are candidates for progenitors of Type Ia supernovae. “We took follow-up images with the GROWTH-India telescope. The observations were made in different optical bands. The nova was seen to decline rapidly in brightness, by 1 - 1.5 magnitudes in the span of 2 days,” says Shubham Srivastav, post-doctoral fellow at the physics department of IIT Bombay (IITB)

GROWTH-India Telescope

1. The GROWTH-India telescope was commissioned six months ago soon after which it saw first light, on the night of June 12.
2. It is part of a multi-country collaborative initiative – known as the Global Relay of Observatories Watching Transients Happen (GROWTH) – to observe transient events in the universe.
3. The fully robotic telescope is designed to capture cosmic events occurring over relatively shorter periods of the cosmological timescale: years, days and even hours.
4. Universities and research institutes from the US, the UK, Japan, India, Germany, Taiwan and Israel are part of the initiative.
5. Their primary research objective is time-domain astronomy, which entails the study of explosive transients and variable sources (of light and other radiation) in the universe.

Nova Observation

1. The telescope has been taking readings since then, and this is the first ‘follow-up’ work.
2. The celestial object was first noticed by a different group which saw the nova explosion.
3. Though a small step in astronomy but it is a big leap, because it is the first scientific result obtained by this telescope.

Details of the Nova

1. Novae are explosive events involving violent eruptions on the surface of white dwarf stars, leading to temporary increase in brightness of the star.
2. Unlike a supernova, the star does not go on to die but returns to its earlier state after the explosion.
3. This recurrent nova, named M31N-2008, has been observed to erupt several times, the most recent eruption happening in November 2018.
4. Transient phenomena such as supernovae are important parts of time-domain astronomy which is a less-explored frontier in astronomy.
5. Such an explosion is when the inner material of the star is thrown out. There is no other way we can actually see what is inside a star.