Ilaria Rosella Pagliaro Thanks to observations from ESO's Very Large Telescope, an exoplanet has been confirmed around Barnard's Star, the closest single star system to the Sun
©ESO
Using the Very Large Telescope of the European Southern Observatory, astronomers have just detected a new exoplanet orbiting Barnard’s Star, which up until now had been the closest single star to our Sun. The fruit of five painstaking years of observations, this has brought to light a peculiar world: Barnard b is a planet with at least half the mass of Venus, clasping its star in just 3.15 Earth days. But what’s really amazing is its surface temperature: a toasty 257°F, quite inhospitable for life as we know it.
While the confirmation of Barnard b is exciting enough, the data hint at signals from no less than three additional exoplanets circling the star. These remain candidates for confirmation. This research represents a major scientific effort; exoplanets around such red dwarf stars as Barnard offer a rare opportunity for the study of rocky worlds.
The red dwarf’s very special habitable zone
The habitable zones around red dwarfs are far closer in to their star compared with stars like our Sun, which would mean those planets could be observed more frequently and in greater detail. While Barnard b does lie outside of such a habitable zone, its discovery nonetheless represents an important step toward the goal of searching for alien worlds.
A long-awaited discovery
It is a story of patience rewarded in the case of Barnard b: “We knew that sooner or later one would appear, and here it is”, said Jonay González Hernández, a researcher at the Instituto de Astrofísica de Canarias and first author of this work.
Such a finding was made possible thanks to the help of ESPRESSO-a highly precise instrument able to measure stellar wobble caused by planetary presence. Other exoplanet-hunting instruments, including HARPS at ESO’s La Silla Observatory, have confirmed such measurements. These new findings, however, come in contradiction to the news announced in 2018 of the existence of another planet around Barnard. For now, nothing is confirmed.
Although Barnard b is extremely hot and enjoys a close-in orbit, its diversity fascinates us by showing us that the universe is teeming with worlds beyond our wildest imagination. The future of exoplanet research seems even more exciting, especially with the construction of the Extremely Large Telescope. This heavy artillery might enable us to study the atmospheres of such rocky worlds and further broaden our understanding of extrasolar planets.
Source: ESO
