Scientists Discover New Extrasolar Planet Dubbed 'Hot Jupiter', Temperature Reaches 1700 Degrees Celsius

JAKARTA - An exoplanet that is claimed to be bigger than Jupiter has been discovered by scientists from India, who are under the auspices of the Department of Outer Space of the Physical Research Laboratory (PRL) in Ahmedabad.

Orbiting close to a very old star, this exoplanet has a mass 1.5 times greater than the Sun. It lies 725 light-years away and is about 70 percent more massive than Jupiter, and about 1.4 times more massive.

According to the Indian Space Research Organization (ISRO), the exoplanet was discovered by Professor Abhijit Chakraborty and a team of students, fellow professors and collaborators from around the world.

This planet is called TOI1789. The exoplanet takes 3.2 days to complete one orbit, implying it is much closer to its central star than Jupiter, which takes 12 years to complete one orbit.

Its proximity to the Sun means the planet is extremely hot, its temperature alone is known to run in excess of 1700 degrees Celsius, making it one of the lowest density planets ever discovered and only 10 of its kind have been discovered to date.

"Such exoplanets that are less than 0.1 AU from their host starting with masses between 0.25 and several Jupiter masses are known as Hot Jupiters," ISRO said as quoted by the Hindustan Times, Monday, November 22.

To find the planet, scientists used the PRL Advanced radial-velocity gray-sky search (PARAS) spectrograph telescope, which is the first device of its kind in India. This telescope is located at the Mount Abu observatory. Measurements for this Hot Jupiter exoplanet were made between December 2020 and March 2021.

The findings have been published in the journal Monthly Notices of the Royal Astronomical Society in a paper entitled "Discovery of a hot Jupiter bubbling around the slightly evolved star TOI-1789."

It is the second exoplanet identified at PRL by astronomers using PARAS on the 1.2 m Mount Abu telescope. The first discovery was K2-236b, a sub-Saturn-sized exoplanet discovered in 2018 that is about 600 light-years away.