An international team of scientists led by Professor Abhijit Chakraborty of the Physical Research Laboratory (PRL), Ahmedabad, has discovered the densest alien planet, which is 13 times bigger than Jupiter. It is said to be orbiting too close to its host star, and researchers have identified its reason. This is the third exoplanet to be discovered from India and by the PRL scientists. The details of the finding have been published in the journal Astronomy & Astrophysics Letters.
The Department of Science and Technology funded the research as part of its National Mission for Planetary Astronomy program, a flagship initiative under the Ministry of Science and Technology. It was carried out by the exoplanet search and study group at PRL, with support from the Indian Space Research Organisation (ISRO), a press release from the institute said.
To study the planet, which has been nicknamed TOI 4603 b or HD 245134 b, astronomers used the indigenous PRL advanced radial-velocity Abu-sky search spectrograph (PARAS) at the 1.2-meter telescope of Gurushikhar Observatory in Mount Abu. This instrument allows precise mass measurements. The team assigned a 14 g/cm3 mass to the planet. The researchers also used NASA’s Transiting Exoplanet Survey Satellite (TESS) to recognize the existence of a companion object with this star and confirm its status as a planet.
The discovery has implications for understanding how these hot, gaseous planets can form so close to their host stars and for the search for extraterrestrial life. The study also shows that more minds and telescopes are better than one, boosting the ongoing global effort to find planets like ours.
This planet is 731 light-years away, in the constellation Cancer (The Crab). It takes seven days to go around its sun and has a surface temperature of 1396 degrees Celsius. Its unique feature is that it has a mass between that of giant planets and low-mass brown dwarfs, and the researchers say it is one of the five exoplanets known to have this sort of mass.
The planetary system, 55 Cancri e, was first noticed by Harvard grad student Rebekah Dawson and her postdoc advisor, Daniel Fabrycky, who trained the MOST space telescope of Canada on the star to observe tiny brightness dips caused when the planet passed in front of — or transited — the star from the telescope’s perspective. This is the same technique used by the prolific Kepler space observatory, which has found 1,235 exoplanets to date, including 55 Cancri e. The researchers continue to study the system and hope to determine its characteristics, such as how much it may vary in size as it orbits. They also plan to investigate whether the planet might have a thin atmosphere, as is often suspected. In addition, they hope to measure the star’s temperature and its companion planet to learn more about how they formed. Finally, they plan to study whether 55 Cancri e is a member of a cluster of exoplanets.
