News by Shuchi Giridhar
A team of scientists from the Physical Research Laboratory (PRL) in Ahmedabad, under the Space Department, have a found a new exoplanet bigger than Jupiter.
The planet has been found orbiting very close to an evolved star. The star has a mass 1.5 times
that of the sun and is located about 725 light years away from the solar system. The exoplanet is about 1.4 times the size of Jupiter. PRL’s advanced radial-velocity Abu-sky Search (PARAS) optical fiber fed spectrograph was used to make the discovery.
The telescope is the first of its kind in India. The discovery team consists of Professor Abhijit
Chakraborty, his team members, students, and international associates from Europe and the US.
What is an exoplanet?
A planet that orbits a star outside our solar system is called an exoplanet. As you already know, our Sun is one star which supports a few planets and many asteroids and dwarf planets (small planets). Just like that, other stars can have their own planets too. A planet that is outside (exo) our solar system is called an exoplanet.
This is the second exoplanet discovered by these researchers using the PARAS telescope. The first one, named K2-236b, about the size of Saturn, is about 600 light years away.
The measurement of the exoplanet was done between December 2020 and March 2021. The star discovered is known as HD 82139.
The newly discovered star and planet system is very unique as the planet finished orbiting the star in just 3.2 days. The planet is quite close to the star, and the distance between the planet and star is barely one tenth of the distance between the sun and Mercury.
Less than ten such close systems have been found among the many exoplanets known to us.
Because the planet and the star are so close to each other, the planet is very hot, with its surface temperature sometimes reaching up to 2000k. This causes an inflated radius, making it one of the known planets with lowest density. Such planets are known as hot Jupiter.
This discovery will help us understand the reason for the inflation of the various hot Jupiters. This discovery has been published in the journal Monthly Notices of the Royal Astronomical Society.