An international team of astronomers has discovered a new, hot, bulging exoplanet called “super-Neptune” using NASA’s Transiting Exoplanet Survey Satellite (TESS). The newly discovered alien world, designated TOI-2498 b, is about six times larger and 35 times heavier than Earth. The opening aired on May 16. Monthly Notices of the Royal Astronomical Society.

TESS surveys about 200,000 of the brightest stars near the Sun in search of transiting exoplanets, ranging from small rocky worlds to gas giants. To date, approximately 6,600 candidate exoplanets (TESS Objects of Interest or TOIs) have been identified, of which 331 have been confirmed to date.

One of the stars TESS observed during its primary mission was TOI-2498 (also known as TIC-263179590), a G-solar star about 26% larger and 12% larger than the Sun. TESS observed TOI-2498 from December 12, 2018 to January 6, 2019, which led to the detection of a crossover signal in the light curve. The planetary nature of this signal was confirmed by further spectroscopic and photometric observations by astronomers led by Ginger Frame of the University of Warwick, England.

“In this paper, we present the discovery of a hot bulging super Neptune passing through a G-type star. Our analysis includes photometry from TESS Sector 6 and Sector 33, tracking ground-based photometry from LCOGT, and spectroscopy from HARPS,” the researchers wrote.

The newly discovered planet has a radius of about 6.06 Earth radii and an estimated mass of 34.62 Earth masses, giving it a density of 0.86 g/cm. ³ . It orbits the parent star at a distance of about 0.05 AU every 3.74 days. The calculated equilibrium temperature of the planet is approximately 1443 K.

Based on the results, the Frame team classified TOI-2498b as a hot and puffy “super-Neptune.” The low density of the planet indicates the presence of a gas shell that makes up about 27% of its mass. But the astronomers added that their planetary model did not predict the water content or significant metallicity in TOI-2498 b’s atmosphere.

In summary, the researchers noted that TOI-2498b is a stable “super-Neptune” that undergoes very little evaporation over its lifetime relative to its mass. They suggest that after formation the planet may have initially emerged as a loose earth the size of Saturn, about 8 to 10 times the size of Earth, and with a crustal mass fraction of 30 to 45%. The age of the planet is estimated to be about 3.6 billion years.

“We found that TOI-2498 b likely began life as a loose Earth the size of Saturn before shrinking to its current size within 3.6 ± 1.1 billion years,” the authors of the paper write.