EPIC 220504338b: Dense 'hot Jupiter' exoplanet orbiting a sun-like star discovered

Artist’s impression of a 'hot Jupiter'. Image credit: Ricardo Cardoso Reis (CAUP)

Washington: Astronomers have discovered a dense "hot Jupiter", an exoplanet transiting a distant six-billion-year-old Sun-like star located about 1,800 light years from the Earth.

The newly discovered planet, designated EPIC 220504338b, was discovered using photometry from Campaign 8 of the Kepler-2 (K2) mission and high-resolution spectroscopic follow up obtained with the FEROS spectrograph.

Researchers led by Nestor Espinoza of the Pontifical Catholic University of Chile conducted follow-up observations using European Organisation for Astronomical Research in the Southern Hemisphere's (ESO) Fibre-fed, Extended Range, Echelle Spectrograph (FEROS).

FEROS spectroscopic observations allowed the team to perform radial velocity measurements that confirmed EPIC 220504338b is a dense "hot Jupiter" transiting a solar analogue as well as provided initial stellar parameters of its host star.

"We have presented the discovery of EPIC 220504338b, a new hot Jupiter orbiting a metal-rich solar analogue discovered using photometry from Campaign 8 of the K2 mission and follow-up radial velocities using the FEROS spectrograph," researchers said.

The "hot Jupiters" like EPIC 220504338b are gas giant planets, similar in characteristics to the solar system's biggest planet, with orbital periods of less than 10 days.

They have high surface temperatures, as they orbit their parent stars very closely, 'Phys.Org' reported.

According to the research, EPIC 220504338b, which was first spotted by NASA's Kepler K2 mission, is about 10 per cent smaller than Jupiter and about 30 per cent more massive. The exoworld orbits its six-billion-year-old Sun-like parent star every 5.8 days.

With a density of nearly 2.1 grammes per cubic centimetre and an equilibrium temperature of about 886 degrees Celsius, the planet is one of the densest "hot Jupiters" below two Jupiter masses known to date.

The newly discovered planet's mass and radius should be on the order of at least 110 Earth masses, researchers said.

Researchers presented their findings in a paper published November 23 on arXiv.org.

(With PTI inputs)