New York: An international team of astronomers has discovered a “hot Jupiter” exoplanet that is so massive and close to its parent star that it influences the star’s rotation with its gravity, media reported. The planet, called HATS-18b, is about 2,100 light years away, Popular Mechanics reported on Tuesday.
Hot Jupiters are giant exoplanets that orbit close to their parent stars. Also known as roaster planets, they orbit their stars in a short time and can be easily observed in transit. The newly discovered exoplanet orbits its star in just 0.84 days, has a radius about 1.34 times that of Jupiter, and has twice the mass of the Jovian gas giant in our solar system, the report said.
The research team was led by Kaloyan Penev of Princeton University. “The high planet mass, combined with its short orbital period, implies strong tidal coupling between the planetary orbit and the star,” said the researchers.
“In fact, given its inferred age, [the star] HATS-18 shows evidence of significant tidal spin up,” the authors said.
The new findings were presented in a paper published online on arXiv.org. “The HATS-18 system is among the best systems (and often the best system) for testing a multitude of star–planet interactions, be they gravitational, magnetic or radiative, as well as planet formation and migration theories,” the authors noted.