Planet orbiting ‘very small’ star found by scientists

Astronomers have discovered an unusual planetary system consisting of a planet the same size as Jupiter orbiting a star only 4 times the size of the solar system’s gas giant – considered too small to have a planet with these characteristics in its orbit.

The exoplanet named after TOI-5205bIt was discovered by a team of astronomers from Carnegie Institute for ScienceShubham Kanodia and described in an article in February 2023 Astronomy Journal.

The star, TOI-5205, is considered a red dwarf. Typically smaller than our sun, these stars are the most common in our galaxy.

Because of their smaller size, they tend to receive about half the sun’s heat, which means they appear brighter and often take on a redder color.

They also have a very long lifespan due to their low luminosity, which allows them to host more planets as they accumulate over time, but the way they form also means they rarely host gas giants.

“It is surprising that it has somehow managed to form a Jupiter-sized planet that is only 4 times the size of its host star Jupiter,” says Kanodia.

Planets form in a rotating disk of gas and dust collected by young stars. The mass is believed to take about 10 light-years to form and form a rocky core at the center of a galaxy, and millions of years to form a gas giant.

Kanodia explained that the existence of TOI-5205b expands what is known about the disks from which these planets were born. “A gas giant is unlikely to form when there is no rocky material to form the initial core, or when the disk evaporates before the large core forms,” ​​he explains.

“However, TOI-5205b occurred. According to our current understanding of the formation of the planet, it should not exist. It’s a ‘forbidden planet’,” he concludes.