PREVIEW

Astronomers using a powerful telescope in Chile have discovered a new planet orbiting Barnard’s star, the closest single star to our Sun.

The new planet, which is about half the size of Venus, takes just over three Earth days to complete one year. Scientists also think there may be three more planets around the same star, but they need more data to be sure.

Barnard’s star is only six light-years away, making it the second-closest star system to us, after Alpha Centauri. Its closeness makes it a prime target for finding planets that might be like Earth. Although scientists thought they found a planet there in 2018, it wasn’t confirmed until now.

The discovery was made after five years of careful observation. Jonay González Hernández, the lead scientist on the study, said, “Even though it took a long time, we always believed we’d find something.” They were looking for planets in the "habitable zone" - the area around a star where water could exist. Red dwarfs like Barnard’s star are good places to search for small, rocky planets.

The newly found planet, called Barnard b, is much closer to its star than Mercury is to our Sun and has a surface temperature of about 125°C. “Barnard b is one of the smallest planets we know about, but it’s too close to the star to have liquid water,” Hernández explained. Even though Barnard’s star is cooler than our Sun, it's still too hot for water to survive on this planet.

The scientists used a very precise instrument called ESPRESSO to detect tiny movements in Barnard’s star caused by the planet's gravity. They also used data from other instruments to confirm the planet. However, their data didn’t support the 2018 discovery.

In addition to this planet, the team found hints of three other possible planets orbiting Barnard’s star. But more observations are needed to confirm if they exist. “We need to keep watching the star to verify these signals,” said Alejandro Suárez Mascareño, another researcher. He added that finding planets like Barnard b, Proxima b, and d shows that small planets are common in our cosmic neighborhood.

A new telescope under construction, called the Extremely Large Telescope (ELT), will help scientists find more small, rocky planets like Barnard b and even study their atmospheres.