Astronomers discover a new giant exoplanet that shouldn’t exist

Astronomers discover a new giant exoplanet that shouldn't exist

One exoplanet that breaks the rules known to the Astronomy It was recently discovered by a group of international experts.

The gas giant, called TOI-4860 b, is an unusual planet for two reasons: Stars of such low mass are not expected to host planets as big as this, which is the size of Jupiter, and this world seems to be particularly enriched with heavy elements.

The study, led by astronomers from the University of Birmingham, was published in Monthly Notices of the Royal Astronomical Society, a magazine specialized in astronomy and gives an account of why there should not be such a world.

The extrasolar planet, or exoplanet, orbits the Red dwarf TOI-4860. Located in the constellation of Corvus. The star TOI-4860 has a mass equivalent to about one-third that of the Sun and the exoplanet orbiting it completes its orbit about once every 1.5 Earth days, classifying it as a “Warm Jupiter.”

This is unusual for two reasons. First, with widths equivalent to about three-quarters that of Jupiter, planets like this are not supposed to form around low-mass stars. Second, TOI-4860 b appears to be enriched with a high proportion of metals, a term astronomers use to describe elements heavier than hydrogen and helium.

“Under the canonical model of planet formation, The less mass a star has, the less massive the disk of material around it is. of that star,” he said. George Dransfield, a member of the University of Birmingham team.

“Since planets are created from that disk, it was expected that high-mass planets like Jupiter would not form. However We were curious about this And we wanted to check the planetary candidates to see if it was possible. TOI-4860 is our first confirmation and also the lowest mass star hosting such a high-mass planet.”

The planet was discovered using the NASA’s Transiting Exoplanet Survey Satellite Like a drop of brightness as it transited in front of its host star, but that data alone was insufficient to confirm that it was a planet.

The team of astronomers used the SPECULOOS South Observatory, located in the Atacama Desert in Chile, to measure the planetary signal at various wavelengths and validate planetary nature. The scientists also observed the planet just before and after it disappeared behind its host star and noticed that there was no change in light, meaning the planet was emitting nothing. Finally, the team collaborated with a Japanese group using the Subaru Telescope in Hawaii. Together they measured the mass of the planet to fully confirm it.

Amaury Triaud, professor of exoplanetology at the University of Birmingham who led the study, said: “I am forever grateful to the brilliant PhD students in our team for proposing to observe systems like TOI-4860. His work has really paid off as planets like TOI-4860 They are vital to deepening our understanding of planet formation.

“One hint of what might have happened is hidden in planetary properties, which seem particularly enriched in heavy elements. We have also detected something similar in the host star, So it is likely that an abundance of heavy elements has catalyzed the process of planet formation,” he added.

The new gas giant takes about 1.52 days to complete a full orbit around its host star, but because its host is a cool, low-mass star, the planet itself can be dubbed “warm Jupiter.” This is a subclass of planet that is of particular interest to astronomers looking to take advantage of their initial observations and Learn more about how these types of planets form.

The team behind the discovery of this exoplanet now intends to search for similar worlds around tinys parent stars using the Very Large Telescope (VLT), located in the Atacama Desert region of northern Chile.

“I am forever grateful to the brilliant PhD students on our team for proposing to observe systems like TOI-4860. The work has really paid off, as planets like TOI-4860 b are vital to deepening our understanding of planet formation,” Triaud concluded.


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