An exoplanet with at least half the mass of Venus orbits Barnard's Star, the closest single star to the Sun, once every 3.15 days.
Barnard's Star is a 10 billion year old red dwarf star located in the constellation Ophiuchus.
At a distance of about 6 light years, it is the second closest star to the Sun after the Alpha Centauri triple star system.
The star, also known as Gliese 699 or GJ 699, is much smaller than the Sun and is classified as an M3.5 dwarf.
Despite the prospect of a “super-Earth” with a mass 3.2 times that of Earth in 2018, no planets have ever been confirmed to orbit this star.
The new exoplanet discovery is the result of five years of observations using the ESPRESSO instrument of ESO's Very Large Telescope (VLT) at the Paranal Observatory in Chile.
“We were always confident that we would find something, even if it took a long time,” said Dr. Jonay González Hernández, an astronomer at the Canarias Astronomical Institute.
The newly discovered planet, named Barnard b, is about 20 times closer to Barnard's star than Mercury is to the Sun.
It orbits its parent star in 3.15 Earth days and has a surface temperature of about 125 degrees Celsius (257 degrees Fahrenheit).
“Bernard B is one of the lowest-mass exoplanets known, and one of the few exoplanets known to have less mass than Earth,” said Dr. González-Hernández. Ta.
“But this planet is too close to its host star, closer than the habitable zone.”
“Even though this star is about 2,500 degrees cooler than the Sun, it's still too hot to support liquid water on its surface.”
In addition to the confirmed planet, astronomers also discovered hints of three more exoplanet candidates orbiting the same star.
However, additional observations are required to confirm these candidates.
“We need to continue observing this star to confirm other candidate signals,” said Dr. Alejandro Suárez Mascareño, also from the Canarias Astronomical Institute and co-author of the study.
“But the discovery of this planet, along with previous discoveries such as Proxima b and Proxima d, shows that our cosmic backyard is full of low-mass planets.”
Bernard B's findings were published in a. paper in diary astronomy and astrophysics.
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JI Gonzalez Hernandez others. 2024. A sub-Earth mass planet orbiting Barnard's star. A&A 690, A79; doi: 10.1051/0004-6361/202451311
Source: www.sci.news
