An exoplanet is a planet that exists outside of our solar system and - unlike Earth - does not orbit the sun but another star. Scientists have discovered over 5000 such exoplanets so far. A research team from India has now discovered another one - with impressive dimensions.

The exoplanet, dubbed TOI-4603b by the researchers, orbits a star 730 light-years away. TOI-4603b is as big as Jupiter - but has a density many times higher than that. The exoplanet has a mass of almost 13 Jupiters, making it more than nine times as dense as this one. Also compared to Earth, the density of the exoplanet is about three times as high.

"It is one of the most massive and densest transiting giant planets known to date," writes the astronomical team led by Akanksha Khandelwal of the Physical Research Laboratory in India. The researchers see it as "a valuable addition", since only very few massive and at the same time nearby giant planets are known. Thus, TOI-4603b could contribute to a better understanding of the formation of planets and their relationship to the stars.

The exoplanet has a tight orbit: it orbits its star in just 7.25 days. Its orbit is said to be distinctly oval or eccentric, suggesting it is still leveling off.

"The discovery of such systems will provide us with valuable insights into the mechanisms of massive planets and improve our understanding of the prevailing formation and migration mechanisms," say the astronomers.

TOI-4603b was first discovered in data from NASA's TESS space telescope. TESS stands for Transiting Exoplanet Survey Satellite and is a highly specialized planet hunter.

Sources: Publication by the researchers in Astronomy