Exoplanet HD 85512 b may be habitable

Modeling habitable zone star HD 85512 has shown that recently found on its orbit exoplanet may be habitable.
Message about the discovery of the planet of the HD 85512, maloprimechatelnoy main sequence stars, was published just two weeks ago. The results of observations made using the HARPS spectrograph at 3, 6-m telescope of the Chilean La Silla Observatory, says that the new minimum mass exoplanet HD 85512 b is 3, 6 ± 0, 5 of the earth, and one revolution around the world, it commits for 58 ± 0 43 13 days, while the 0, 260 ± 0, and 005. e. from it in orbit with an eccentricity of 0, 11 ± 0, 10.

Low weight HD 85512 b makes it one of the least known exoplanets large.

HD 85512, we note, is only 36 light-years away in the constellation Vela. Its weight is estimated at 0, 69 solar luminosity is about 0 126 ± 0 008 solar and effective temperature is 4715 ± 102 K.

The definition of the boundaries of the habitable zone of HD 85512 were engaged three scientists from the Institute of Astronomy. Max Planck (Germany) and the University of Geneva (Switzerland). Habitability criterion authors considered the possibility of prolonged existence of liquid water on a hard surface of the planet that resembles Earth and has the familiar atmosphere of CO2, H2O and N2.

In this formulation, the position of the boundaries of the habitable zone and the equilibrium temperature of the planet depends on the James Bond albedo (the ratio of the entire planet reflected flux to the incident flux on it), semi-major axis and eccentricity of the orbit of the latter, as well as the luminosity of the star. On a planet like HD 85512 b, which is located at the inner boundary of the zone, the greenhouse effect can lead to evaporation of all the water, and this was followed by photodissociation of water vapor and care free hydrogen into space; outside the boundary of the habitable zone of the greenhouse effect, in contrast, can not hold the CO2 condensation, and it ends glaciation.

As shown by the calculations is low enough temperature sufficient to maintain liquid water on the surface of HD 85512 b, in the set, if its albedo of Bond is not less than 0 48 (at the circular orbit) or 0 and 52 (with eccentricity equal to 0, 11). Run these conditions are not so difficult: it is enough to close the clouds more than half the surface of the model exoplanets.


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