Planet Discovered Orbiting Barnard’s Star – Bay Area Telemundo 48
An international team of astronomers has discovered an exoplanet at least half the mass of Venus orbiting Barnard’s Star, the closest to our Sun.
Scientists do not rule out the existence of three other exoplanets in other orbits of the star.
Located just six light-years away, Barnard is the closest single star to us, the fastest in the night sky, and the second closest star system in the neighborhood, after the three-star group Alpha Centauri.
Because of its proximity, this star is a prime target in the search for Earth-like exoplanets, but as of 2018, when a team of astronomers discovered a super-Earth orbiting Barnard, no other planets had been discovered in its orbit .
This exoplanet, a super-Earth with 40 percent the mass of Earth and an orbit of about 233 days, had characteristics that made life as we know it unsustainable.
The new exoplanet, discovered with the help of the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in Chile, “is completely different” but just as inhospitable to host life, explained Alejandro Suárez Mascareño in statements . to EFE, researcher at the Spanish Institute of Astrophysics of the Canary Islands (IAC) and co-author of the study.
Details of the new planet, called Barnard b, were published this Tuesday in an article in the journal Astronomy & Astrophysics and are the result of observations made over the past five years.
“Even though it took us a long time, we were always sure we could find something,” said Jonay González Hernández, an IAC researcher and lead author of the paper.
Around Barnard
The team was looking for signs of possible exoplanets within Barnard’s Star’s habitable or temperate zone, the region where liquid water can exist on the planet’s surface.
Often, the astronomical community focuses on the study of red dwarfs (like Barnard) because low-mass rocky planets are easier to detect in their environments, something more complicated to do if we are talking about larger stars, similar to the Sun.
The new exoplanet, Barnard b, is twenty times closer to Barnard’s star than Mercury is to the Sun, “has a surface temperature of about 125 ºC and an orbital period of 3.15 Earth days,” explained Suárez Mascareño.
“Barnard b is one of the lowest-mass known exoplanets and one of the few known with a mass less than that of Earth. But the planet is very close to the host star,” added González Hernández.
“Even if the star was about 2,500 degrees cooler than our Sun, it is still too hot to sustain liquid water on the planet’s surface,” the lead author concluded.
A super-earth that doesn’t exist
To do this study, the team used ESPRESSO, a high-precision instrument that measures the wobble of a star caused by the gravitational pull of one or more orbiting planets.
Astronomers take advantage of this phenomenon to measure with astonishing precision the changes in a star’s velocity due to an orbiting exoplanet.
Barnard b’s finding was also confirmed by data from other instruments also specialized in the search for exoplanets: HARPS, at ESO’s La Silla Observatory, HARPS-N and CARMENES.
However, the new data has not confirmed the existence of the super-Earth reported in 2018. “We have not been able to confirm its existence and, in fact, at this time the general consensus is that this exoplanet could not exist,” Suárez Mascareño advanced to EFE.
“But we believe that Barnard’s star could have up to three more exoplanets orbiting it, although for now we only have indications that we cannot confirm,” the IAC researcher stressed.
For this, we should continue to observe Barnard’s star “but 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 researcher emphasized.
ESO’s Extremely Large Telescope, under construction, will feature the ANDES instrument that will allow the scientific community to detect more of these small rocky planets in the temperate zone around nearby stars and study the composition of their atmospheres.