2023-08-04 12:34:49
An international team of scientists has discovered an unusual Jupiter-sized exoplanet orbiting a low-mass star called TOI-4860located in the constellation of Corvus (The Raven).
The newly identified gas giant, named TOI-4860 bis an unusual planet for two reasons: such low-mass stars are not expected to host Jupiter-like planets, and furthermore, this planet appears to be particularly enriched with heavy elements.
TOI-4860 b is an unusual planet in that low-mass stars are not expected to host Jupiter-like planets like this, and it is rich in heavy elements.
The study, led by astronomers from the University of Birmingham, is published this week in the journal Monthly Notices of the Royal Astronomical Society.
The planet was initially identified with the Transiting Exoplanet Survey Satellite (TESS) from NASA as a bright speck as it transited in front of its star, but the data was insufficient to confirm the type of object it was.
The team then used the Observatory Sur SPECULOOSlocated in the Atacama desert (Chile), to measure the object’s signal at different wavelengths and validate its planetary nature.
SPECULOOS Southern Observatory in Chile. /ESO/G. Lambert
The astronomers also observed it just before and after it disappeared behind its host star, noting that there was no change in light, meaning the planet was not emitting any.
Lastly, the team collaborated with a Japanese group using the Subaru Telescope in Hawaii, USA, to measure the planet’s mass for definitive confirmation.
PhD student finding
Tracking the star TOI-4860 and the confirmation of its planet was the initiative of a group of PhD students from the SPECULOOS project.
George Dransfieldone of these students who has just presented his thesis, explains: “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,” he continues, “it was expected that high-mass planets like Jupiter would not form. However, we were curious about this and wanted to check out the planet candidates to see if it was possible. TOI-4860 is our first confirmation and also that a lower-mass star harbors such a high-mass planet.”
For his part, Amaury TriaudProfessor of Exoplanetology at the University of Birmingham who led the study, notes: “Planets like TOI-4860 b are vital for deepening our understanding of planetary formation.”
Planets like TOI-4860 b are vital to deepen our understanding of planetary formation.
Amaury Triaud (University of Birmingham)
“A clue to what might have happened lies in the planetary properties, which seem particularly heavy element-enriched,” he adds, “and we’ve also detected something similar in the host star, so it’s likely that an abundance of heavy elements catalyze the process of planetary formation”.
Day and a half to complete its orbit
It takes the new gas giant about 1.52 days to complete a full orbit around its host star, and since the host star is cold and low in mass, the planet itself can be called a ‘hot jupiter‘. This is a subclass of planets of special interest to astronomers who want to learn more about how these types of planets form.
Mathilde Timmermansanother SPECULOOS project student working at the University of Liege (Belgium), concludes: “Thanks to its very short orbital period and the properties of its host star, the discovery of TOI-4860 b provides a brilliant opportunity to study the properties of atmospheres of a hot Jupiter and learn more about how gas giants form.
Fuente: University of Birmingham
Rights: Creative Commons.
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