Scientists at the Ahmedabad-based Physical Research Laboratory (PRL), under the Department of Space, have discovered a new exoplanet orbiting too close to an evolved or aging star with a mass of 1.5 times that of the Sun and located 725 light years away.
The exoplanet’s mass is found to be 70% and size about 1.4 times that of Jupiter. The discovery was made using PRL’s advanced radial-velocity abu-sky search (PARAS) optical fiber-fed spectrograph, the first of its kind in India, on the 1.2-metre telescope situated at Mount Abu observatory.
Artistic impression of the TOI-1789 star-planet system, along with characteristics of planet. (Photo: Isro)
The measurements were carried out between December 2020 and March 2021. Further follow-up measurements were also obtained from Germany’s TCES spectrograph in April this year.
The star around which the planet is orbiting is referred to as HD 82139 or TOI 1789. The newly found exoplanet will be called HD 82139b or TOI 1789b.
Dubbed TOI 1789b, this new exoplanet is bigger than Jupiter and is the second discovery made by the PRL as it first discovered a world outside the solar system named K2-236b in 2018. The latter is a sub-Saturn-sized planet and is located 600 light-years away.
For scaling, the distance is just one-tenth the distance between Mercury and the sun. As a result, this proximity makes the exoplanet’s surface temperature reach up to 2000 K. What makes the discovery even more special is that there are less than 10 such close-in systems of exoplanets discovered so far.
The discovery team includes Prof Abhijit Chakraborty, students and his team members, and international collaborators from Europe and the US, an Isro statement stated.
(With PTI inputs)
