Astronomers discover an exoplanet the size of Jupiter with unusual characteristics

The unprecedented features of the gas giant, named TOI-4860 b, surprised astronomers. The unusual find was first identified using NASA’s Transiting Exoplanet Survey Satellite.

An international team of scientists discovered an unusual Jupiter-sized exoplanet orbiting a low-mass star called TOI-4860, located in the constellation Corvus. The specialists assured that this finding serves to deepen the understanding of planetary formation.

The newly identified gas giant, named TOI-4860 b, is considered an unusual planet for two reasons: stars of such low mass are not expected to host Jupiter-like planets, and the exoplanet appears to be particularly enriched in heavy elements.

The study, led by astronomers at the University of Birmingham, was published in the Monthly Notices of the Royal Astronomical Society. Likewise, in confirming the planet, which was initially identified by NASA’s Transiting Exoplanet Survey Satellite (TESS), several observatories were involved: the SPECULOOS South Observatory, located in the Atacama desert (Chile), and the Subaru telescope from Hawaii.

The monitoring of this star and the confirmation of its planet was the initiative of a group of PhD students from the SPECULOOS project, according to the British university in a statement.

George Dransfield, one of the PhD students who has just presented his thesis in Birmingham, explained that according to the canonical model of planet formation, the less mass a star has, the less massive is the disk of material that surrounds it.

“Since planets form from that disk, it was expected that high-mass planets such as Jupiter would not form. However, we were curious about this and wanted to check out the planet candidates to see if it was possible.” assures the researcher.

According to Dransfield, “TOI-4860 is our first confirmation and also the lowest-mass star to host such a high-mass planet.”

It takes about 1.52 days for the new gas giant to complete one orbit around its host star, and since its host is a cool, low-mass star, the planet itself can be called a “hot Jupiter.”

Professor of Exoplanetology at the University of Birmingham, Amaury Triaud, who led the study, explained that planets like TOI-4860 b are vital to deepening our understanding of planetary formation.

A clue to what could have happened is hidden in the planetary properties, which seem particularly enriched in heavy elements, explains the specialist.

source: https://academic.oup.com/mnrasl/article/525/1/L98/7235807?login=false