Discovered! Icy Super-Earth at Barnard's Star, Our Sun's Neighbor

Rodiano Bonacci
Novembre 15, 2018

Thus, closer studies of Proxima b, Barnard's Star b and other super-Earths should help scientists come closer to figuring out whether the conditions for life are rare or common in the universe.

Our corner of the Milky Way is getting rather neighborly.

Less than six light-years away from our Sun, the potential planet orbits Barnard's Star, a well-studied low-mass red dwarf star in the Ophiuchus constellation. Now, they believe they have found an exoplanet around Barnard's star, which at 6 light-years away is the second-closest star system.

Now that this planet appears to be a real world, Teske says that there are many unanswered questions she hopes to resolve quickly, such as what the surface is made of, or if it has an atmosphere.

Lately, a lot of the exoplanets discovered by astronomers have been incredibly far away.

This is not the first time that Barnard's star has been the focus of attention for exoplanet-hunting astronomers. Spotting planets at a huge distance is still important, and every new planet researchers are able to detect adds to our knowledge of the universe and nature itself, but majority are so distant that we'll likely never actually visit them. But that method detects only the small fraction of planets that cross their star's face when viewed from Earth. So one way or another, Barnard's star will likely make numerous appearances in the headlines over the next few years.

"After a very careful analysis, we are over 99 percent confident that the planet is there", said Ignasi Ribas from Spain's Institute of Space Studies, in a statement.

"The combination of all data led to a total of 771 measurements - a huge amount of information!" "The investment to find them is expensive", said Ribas. As they report today in Nature, they found that the star's light oscillated every 322 days, implying a planet orbiting with a 322-day year. The team has calculated that this is highly unlikely, although still possible.

"We're not making the claim that this is in any way related to the van de Kamp astrometric planets", Ribas says. Madhusudhan isn't quite so certain: "If confirmed, this will be very good".

What was going on? van de Kamp's observations were made using a large refracting telescope, and astronomers eventually realised that the telescope's main objective lens had been cleaned and modified several times during the decades of his study. This would create slight changes in the color of the light from Earth's perspective due to the Doppler effect.

Artist's impression of Barnard's Star b under the orange-tinted light from its red dwarf host.

Because Barnard's star is so close, the separation between the planet and star in the sky will be relatively large.

"Using this spectrum, the characteristics of the planet's atmosphere - such as its winds and rotation rate - could be inferred", Diaz wrote. "This would be a dream".

Even if Barnard's star b is rocky, life would have a hard time taking root on its chilly surface.

The newly discovered world, described in the journal Nature on Wednesday, is associated with a small, dim star known as Barnard's Star that is older than our solar system.

On distance alone, it's estimated that temperatures would be about -150C on the planet's surface.

Madhusudhan thinks the result is a sure sign that astronomers will soon find other arrivistes to the stellar neighborhood. "The question is, how do we detect them?"

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