An international group of astronomers reported the opening of unusual exoplanets toi-1231 B the size of Neptune, located at a distance of about 90 light years from the Earth. It is one of the coldest small planets and is located in the dwelling area of the parent star, which makes it possible to exist on it available observation of clouds from water vapor. Details are set out in preprint article available in the ARXIV repository.
Scientists monitored the TI-1231 B star, belonging to red dwarfs, with the help of the TSS cosmic telescope and recorded two transit signals on the gloss curve – the brightness of the star drops, when a large celestial body passes between it and the observer. Subsequently, more detailed transit data managed to collect with the help of the international network of land telescopes of the LAS Cumbras Observatory and ASTEP photometric tools (Antarctica Search for Transiting Exoplanets) located on the Antarctic Station of Concordia.
It turned out that the shine curves are caused by the planet-twin of Neptune, the radius of which reaches 3.65 radius of the Earth, and the period of treatment around the parent star is equal to just over 24 days. Spectrographic measurements of the radial speed of the star, which occurs with the rejection of the general center of gravity due to the presence of the planet, showed that the mass of the TOI-1231 B is about equal to the 15 grounds of the Earth. Taking into account the size of its density, only a little more neptune density (1.74 grams per cubic centimeter versus 1,638 grams per cubic centimeter, respectively).
Opening agitated by scientists in that the relatively low equilibrium temperature of the planet, equal to 330 Kelvinov, makes the TOI-1231 B suitable for studying atmospheric composition (for example, clouds from water vapor and ammonia nitrogen) during transit. At this point, you can observe how the light of the star passes through the atmosphere of the planet, but certain substances in the atmosphere absorb the waves of a certain length, which is detected when spectrographic analysis as dark lines on the spectrum.
Such a rare opportunity to explore researchers, except the TOI-1231 B, provides only one well-known planet – the cold minineptun K2-18 B, which, as already known, contains water vapor. Future observations using the Hubble and James Webba space telescopes will allow one of its kind a comparative analysis of the gas shells of two planets similar type.