Barnard Star b

The object officially remains a candidate for the planet: the probability that the object has a planetary nature is 99%. A group of researchers who announced the discovery will continue to observe to exclude the possibility of explaining the variability of the brightness and motion of the star by any other reasons.

The assumption about the planet appeared as a result of studying changes in the radial velocity of a star, which is one of the most commonly used methods for planet detection. The oscillations observed in the motion of the Barnard star have a period of about 233 days, which corresponds to a major semiaxis of 0.4 a. e. at the orbit of a companion object. The mass of the proposed planet was estimated at 3.2 Earth masses. Leading astronomer Ignasi Ribas noted that during the study, data from 7 instruments were used, observations were carried out for 20 years, so the resulting data array was one of the most detailed among similar ones when studying radial velocities ^[6] .

The exoplanet is thought to be cold, with a surface temperature of about −170 ° C. Despite the fact that the planet’s orbit is close to the star by the standards of the solar system, it is still outside the snow line of the dim red dwarf, which is Barnard’s star. Near the snow line, volatile components of the interplanetary medium, such as water vapor, condense to form ice; Thus, the planet is outside the habitable zone , where the temperature allows water to be in a liquid state. Astronomers expect to find more such planets near snow lines, since protoplanetary accretion is more likely in this temperature regime.