An Indian team of scientists led by Professor Abhijit Chakraborty of Physical Research Laboratory (PRL), Ahmedabad, have discovered a sub-Saturn or super-Neptune size planet around a Sun-like star.
The planet has a mass of about 27 Earth Mass and size of 6 Earth Radii. It goes around the host star in about 19.5 days.
The host star is about 600 light years away from the Earth.
The discovery was made by measuring the mass of the planet using the indigenously designed ‘PRL Advance Radial-velocity Abu-sky Search’ (PARAS) spectrograph integrated with 1.2m Telescope at PRL’s Gurushikhar Observatory in Mount Abu, India.
How is the size of a planet measured?
Scientists are able to determine the size of a planet on the basis of the amount of starlight it is able to block when it is in transit, which is when the planet body comes in between the star and the observer on the Earth.
About PARAS spectrograph
PARAS is the first-of-its-kind spectrograph in Asia, which can measure the mass of a planet going around a star.
Very few such spectrographs exist around the world (mostly in the US and in Europe) that can do such precise measurements.
The planet will be known as EPIC 211945201b or K2-236b, as the name of the host star is EPIC 211945201 or K2-236.
The surface temperature of the planet is around 600°C, as it is very close to the host star, around 7 times nearer than Earth-Sun distance. Such a close proximity might make the star unhabitable.
The discovery is of importance to understand the formation mechanism of such kind of planets that are too close to their host star and as well as planet formations around Sun-like stars.
Only 23 such planetary systems including this discovery are known to this date with masses between 10 and 70 Earth mass and size of 4 to 8 Earth radii with such precise measurement of mass.
With the discovery, India has joined a handful of countries that have discovered planets around stars.
The research appeared online in the Astronomical Journal of the American Astronomical Society and was published by IOP Publishing.