An international team of astronomers has discovered a new hot Jupiter-sized exoplanet orbiting a dwarf star using NASA’s Transiting Exoplanet Survey Satellite (TESS). The newly discovered alien world, designated TOI-4127 b, is more than twice the size of Jupiter. The finding was reported in an article published on the preprint server on March 25. arXiv.

TESS searches about 200,000 of the brightest stars near the Sun to look for transiting exoplanets. So far, it has identified more than 6,200 candidate exoplanets (TESS Objects of Interest, or TOIs), of which 3,031 have been confirmed.

A team of astronomers led by Arvind F. Gupta of Pennsylvania State University (PSU) has confirmed another TOI view of TESS. They reported that a transition signal was detected in the light curve of a late F-type dwarf known as TOI-4127. The planetary nature of this signal was confirmed by further spectroscopic observations.

“In this paper, we present the TESS discovery of the very eccentric hot Jupiter TOI-4127 b and the verification and characterization of the exoplanet signal by NEID and SOPHIE spectrographs,” the researchers write.

According to the article, TOI-4127 b has a radius of about 1.1 Jupiter radius and a mass of 2.3 Jupiter masses, giving it a density of about 2.17 g/cm.³. The planet orbits its host every 56.4 days at a distance of about 0.31 AU from itself in a very eccentric orbit – with an eccentricity of about 0.75. The equilibrium temperature of TOI-4127 b was estimated to be about 605.1 K, so the planet was classified as “hot Jupiter”.

After analyzing the parameters of TOI-4127 b, the researchers concluded that the planet may be the ancestor of “hot Jupiter”, but only if there is a satellite of concern. The so-called hot Jupiters have similar characteristics to the largest planet in the Solar System, with orbital periods of less than 10 days. Such exoplanets have high surface temperatures because they orbit very close to their parent star.

“Hot Jupiters are predicted to spend part of their lives in high eccentricity tidal migration trajectories if they are subject to age-related eccentricity fluctuations, where they periodically shift angular momentum with a distant perturbation to reach higher eccentricities and smaller pericentric distances than currently observed.” , the authors of the article explained.

In the case of the TOI-4127 system, the current periastron separation of the newly discovered planet is too large for a high eccentricity tidal migration to cross its orbit. The astronomers noted that TOI-4127 b is unlikely to be the hot ancestor of Jupiter unless it exchanges angular momentum with an undetected outer moon. However, no evidence of additional bodies in this system has yet been found.

As for the parent star TOI-4127, it has a radius of almost 1.3 solar radii and a mass of about 1.23 solar masses. The star is about 4.8 billion years old, has a metallicity of 0.14 and an effective temperature of 6096 K.