An international team of scientists led by Professor Abhijit Chakraborty at the Exoplanet Research Group of the Physical Research Laboratory (PRL), Ahmedabad has discovered the densest exoplanet, which has 13 times the mass of Jupiter.

An exoplanet or extrasolar planet is a planet outside the Solar System.

The discovery of this massive exoplanet was made by the team, which includes scientists from India, Germany, Switzerland and the USA, using the indigenously made PRL Advanced Radial-velocity Abu-sky Search spectrograph (PARAS) at the 1.2 m telescope of PRL at its Gurushikhar Observatory in Mount Abu by measuring the mass of the planet precisely.

This is the third exoplanet that has been discovered from India, and by the PRL scientists, following the discoveries in 2018 (K2-236b) and 2021 (TOI-1789b).

The findings of this study is published in the journal Astronomy & Astrophysics Letters.

The newly discovered exoplanet is found around the star called TOI4603 or HD 245134.

NASA’s Transiting Exoplanet Survey Satellite (TESS) initially declared TOI4603 as a possible candidate to host a secondary body of unknown nature.

Using PARAS, scientists discovered it as a planet by measuring the mass of the secondary body and hence the planet is called TOI 4603b or HD 245134b.

The planet is located 731 light years away from Earth and orbits its star every 7.24 days. The planet is raging hot with a temperature of 1396 degrees Celsius.

In a statement, the Indian Space Research Organisation (ISRO) said that what sets this discovery apart is that the planet falls into the transition mass range of massive giant planets and low-mass brown dwarfs with masses ranging from 11 to 16 times the mass of Jupiter.

Only fewer than five exoplanets are currently known in this mass range so far, it said.

According to ISRO, massive giant exoplanets have mass greater than four times that of Jupiter.

"The newly discovered exoplanet TOI 4603b is one of the most massive and densest giant planets that orbits very close to its host star at a distance less than 1/10th the distance between our Sun and Earth," ISRO said.

The exoplanet with a surface temperature of 1670 K is likely undergoing high-eccentricity tidal migration with an eccentricity value of approximately 0.3, it added.

"The detection of such systems provides valuable insights into the formation, migration, and evolution mechanisms of massive exoplanets," the Indian space agency said.