Astronomers have found evidence for the presence of extrasolar planets at Barnard’s star is the nearest single star. It belongs to the class of red dwarfs and is the constellation Ophiuchus about 6 light years from Earth. At present near the star planetary body scientists has prompted anomalies, which were observed in the motion of the star. About the study of astronomers reported in the article of the journal Nature.
Red dwarfs are much smaller and cooler than our Sun, but at the same time can show changing activity, “fading”, then starting to cast stellar flare in the surrounding space. The researchers however note that Barnard’s star is one of the most peaceful ever discovered red dwarfs.
The relatively modest activity of star created interest for scientists who tried to find new exoplanets around her. However, for a very long time to do this was not possible per se, despite the use of different search methods. And yet scientists have observed in the movement of the stars are strange “vibrations”, which cannot be attributed to normal error in the observations. To examine in more detail the issue decided by the team of international scientists led by astrophysicist Ignasi Ribas.
“It was not a revelation for us. In fact, even in 2015, we noted the presence of a signal in the archived data of observations with different astronomical instruments. Nevertheless, the statistical data in order to be able to make a clear conclusion was not enough”, comments in astrophysics, Institute of space Sciences, Ignasi Ribas.
After a careful study of the signal, the researchers had a clearer idea of what they actually see. The astronomers analyzed data on the radial velocity of the star, collected over two decades with seven different spectrometers and carefully filtered out all the possible statistical error and noise.
“We are pretty sure that you can see periodic oscillations with an amplitude of 1.2 meters per second with an interval of 233 days. This may indicate the presence in the system of the planet. At the same time, this anomaly may be due to certain phenomena occurring on the surface of a star,” explains Ribas.
To exclude these phenomena and to explain the observed anomalies, scientists have conducted numerous computer simulations. In the end, it turned out that the probability of observing a homogeneous signal 233 every day, due to the activity of the star, namely the star spots on the surface of the stars that can really create such fluctuations in the movement of the sun, will actually be less than 0.8 percent.
“After all the tests we came to the conclusion that the Keplerian reflex motion in this case may explain the presence in the system of the planet. At the moment in this conclusion we are confident 99.2 percent,” adds Ribas.
Based on these data, scientists make the assumption that detected a potential super-Earth – mass planet bigger than Earth, but smaller than the ice giant Uranus. The object is most likely located on the “snow border” Barnard’s star. We are talking about the distance from the star where the temperature is low enough to simple volatile compounds (such as water, ammonia, methane, molecular nitrogen and chlorine) was passed into the solid state, forming in the end the planet.
And yet very many details about a potential exoplanet scientists is still unknown.
“We know virtually nothing about its composition and characteristics. Weight, likely 4 times larger than the earth. The planet can be rocky, and belongs to a class of soft mini-Neptune class gas dwarfs. In any case, it must be a very cold world as its equilibrium temperature is about -170 degrees Celsius,” — noted the researchers.
Ribas and his colleagues are going to continue to study Barnard’s star. Who knows, maybe this red dwarf hides several planets.
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