Barnard’s star is a dim, cool star about one-seventh the mass of our Sun.
Unlike the nearest star to the Sun (Proxima Centauri, a little over four light-years away in the Alpha Centauri star system), Barnard’s star zips through the cosmos alone.
As EarthSky points out, Barnard’s star is much less powerful than the Sun; if we orbited that star instead of the Sun, life as we know it would not be possible.
The star—dubbed Barnard b—is about twenty times closer to its host star than Mercury is to our Sun, and whips around Barnard’s star in just over three Earth days.
Barnard’s star was previously suspected to host exoplanets in its orbit—there was promising evidence in 2018, but no certain confirmation—until now.
Recent observations of the celestial body have shown that the single closest star to the Sun—that is, the closest star moving independently from a star system—has at least one exoplanet.
Results from five years of observational data collected at Chile’s Paranal Observatory with the Very Large Telescope of the European Southern Observatory are described in the team’s research, which was published today in Astronomy and Astrophysics.
Approximately six light-years from Earth, the small planet revolves around Barnard’s star, a red dwarf. A cool, dim star, Barnard’s star has a mass of roughly one-seventh that of our Sun. Barnard’s star is faster than any other star in the universe, even faster than Proxima Centauri, which is located in the Alpha Centauri star system and is slightly over four light-years away from the Sun. Since Barnard’s star is far weaker than the Sun, life as we know it would not be possible if we orbited it instead of the Sun, as EarthSky notes.
As a thermometer reads, the same could be said for the erratic exoplanet, but in the other direction. Barnard b, the star, orbits Barnard’s star in less than three Earth days and is roughly twenty times closer to its host star than Mercury is to our Sun. With a surface temperature of about 257° Fahrenheit (125° Celsius), the exoplanet is understandably piping given its closeness to the sun.
The lead author of the study, Jonay González Hernández, who works as a researcher at the Instituto de Astrofísica de Canarias in Spain, stated in an ESO release that Barnard b is among the few known exoplanets with a mass comparable to Earth.
Although there was encouraging evidence in 2018 but no concrete confirmation, Barnard’s star was previously thought to harbor exoplanets in its orbit.
The team’s goal was to find exoplanets circling Barnard’s star that might be in the habitable zone, also known as the “Goldilocks” zone, which is the range from a host star where a planet’s surface can support liquid water. Life as we know it is impossible on the exoplanet because it does not.
In the same press release, study co-author Alejandro Suárez Mascareño, a researcher at the Instituto de Astrofísica de Canarias, stated, “The discovery of this planet, along with other previous discoveries such as Proxima b and d, shows that our cosmic backyard is full of low-mass planets.”.
The team also reported in their most recent paper that there is evidence of at least three additional exoplanet candidates in the vicinity of Barnard’s star, but further observations are required to determine which of those candidates are real exoplanets.
We can only hope that more discoveries of these nearby alien worlds will come from the next generation Extremely Large Telescope and other projects like the Webb Space Telescope and the Transiting Exoplanet Survey Satellite (TESS).
