Astronomers discover exoplanet near the Solar System – 10/01/2024 – Science

A rare exoplanet smaller than Earth has been discovered orbiting one of the closest stars to the Sun, although its surface is too hot to support life, a group of astronomers reported this Tuesday (1st).

The planet orbits Barnard’s star, which is just six light-years away, according to observations carried out over five years by the Very Large Telescope installed in the Chilean desert.

Astronomers look for planets that are in the “habitable zone” of their respective suns, where it is neither too hot nor too cold to prevent the existence of liquid water, which is considered an essential ingredient for life.

The newly discovered exoplanet, named Barnard b, is outside the habitable zone.

The Barnard star is a red dwarf, much cooler than the Sun, and the exoplanet orbits very close (at a much smaller distance than Mercury from the Sun), which raises the estimate of a surface temperature of 125ºC and one year of planet only lasts three Earth days.

“Barnard b is one of the lowest-mass exoplanets known and one of the few with a mass less than Earth,” said Jonay González Hernández, a researcher at the Canary Islands Institute of Astrophysics in Spain and lead author of the study published in the journal Astronomy and Astrophysics.

“Although the star is approximately 2,500ºC cooler than our Sun, it is too hot there for liquid water to exist on the surface,” González added.

Barnard is located in the constellation Ophiuchus. After the three stars in the Alpha Centauri system, 4.2 light years away, it is the closest to Earth.

Astronomers detect exoplanets when they pass in front of their star, so the closer they orbit, the more likely they are to observe them.

The researchers also found evidence of three other possible exoplanets orbiting Barnard, but they need more observations to confirm their findings.

The discovery, along with two exoplanets orbiting the star Proxima Centauri, “shows that our cosmic neighborhood is full of low-mass planets,” said Alejando Suárez Mascareño, co-author of the study.

Since the 1990s, more than 5,700 planets have been discovered outside the Solar System, but few are in the habitable zone.