Russian astronomers revisited structure of three exoplanets
The astronomers from Special Astrophysical Observatory RAS using six-meter optical telescope BTA-6 have examined possible exoplanets KOI-974.01, KOI-2687.01/02, and KOI-2706.01. Herewith, they have managed to approve the planet character and also discover in the system КОI-974 some marks of one more large planet.
By using a spectrograph at BTA-6 telescope, the authors have shown that all possible exoplanets KOI-974.01, KOI-2687.01/02, and KOI-2706.01 have masses lower that twelve-fold mass of Jupiter. The space bodies of such size are conventionally classified as exoplanets, while larger objects belong to brown dwarfs. Up to now, the status of these three objects remained questionable, as they could be attributed to brown dwarfs and even to dim secondary stars in corresponding systems.
According to newly obtained data, the radii of two among three inspected stars have appeared to be larger as it has been supposed in «Kepler» catalog. This implies that also exoplanets KOI-974.01 и KOI-2706.01 are larger than it has been thought before. For example, the KOI-974.01 is not an Earth-like planet but a relatively large space body with the sizes possibly closer to Neptun.
Another surprise for researchers is the fact that in the system KOI-974 the local star is trembling in such a way as if its rotation among figure axis is influenced by the presence of a space body, possibly another planet, located in the proximity of the star. The authors are planning to proceed to track these and also other possible exoplanets discovered within the «Kepler» project to get more precise evaluations of the masses of these exoplanets.
The research article has been recently published in the Russian journal Astrophysical Bulletin.
Before, an international team of astronomers has discovered the nearest to the Earth exoplanet which might be inhabited.