Summary:
Bengaluru, Nov 17 (PTI) The exoplanet search and study group at the Ahmedabad-based Physical Research Laboratory (PRL), has discovered a new exoplanet orbiting too close to an evolved or aging star with a mass of 1.5 times that of Sun and located 725 light years away, according to Indian Space Research Organisation.This discovery was made using PRL Advanced Radial-velocity Abu-sky Search (PARAS) optical fiber-fed spectrograph, the first of its kind in India, on the 1.2 metre Telescope of PRL at its Mt.
Abu Observatory, the Bengaluru-headquartered space agency said in a statement.Using PARAS, which has the capability to measure mass of an exoplanet, the exoplanet"s mass is found to be 70 per cent and size about 1.4 times that of the Jupiter, it said.These measurements were carried out between December 2020 and March 2021.
Further follow-up measurements were also obtained from TCES spectrograph from Germany in April 2021, and also independent photometric observations from the PRL"s 43-cm telescope at Mt.
Abu.The star is known as HD 82139 as per the Henry Draper catalogue and TOI 1789 as per the TESS catalogue.
Hence, the planet is known as TOI 1789b or HD 82139b as per the IAU nomenclature.The discovery team led by Prof.
Abhijit Chakraborty, includes students and team members, and international collaborators from Europe and the US.This newly discovered star-planet system is very unique -- the planet orbits the host star in just 3.2 days, thus placing it very-very close to the star at a distance of 0.05 AU (roughly one tenth the distance between Sun and Mercury).There are less than 10 such close-in systems known among the zoo of exoplanets known so far.