Astronomers using ground-based telescopes have refined the physical parameters of the super Neptune WASP-107b. It turned out that it has an unusually massive atmosphere, and the average density of the exoplanet is several times less than the density of water. This suggests that astronomers will have to revise the theory of the formation of exoplanets, in particular gas giants. The article was published in The Astronomical Journal.
To date, astronomers are aware of the existence of several thousand exoplanetary systems, which has led to a number of new questions regarding the formation of planets. For example, the mechanisms of formation, evolution and migration of hot Jupiters and sub-Neptuns do not fit well with current theories, which were originally developed solely on the basis of observations of the planets of the solar system. Scientists are also interested in understanding the boundary between the ice and gas giants; for these studies, observations of exoplanets are needed, the masses of which are in the interval between the masses of Neptune and Saturn.
A group of astronomers led by Caroline Piaulet from the Institute for Exoplanet Research in Montreal published the results of the analysis of data from spectroscopic observations of the exoplanet WASP-107b using the CORALIE instrument installed on the Leonard Euler telescope and HIRES (High Resolution Echelle Spectrometer) installed on the telescope Keck Observatory.
WASP-107b is located in the orange dwarf system located 208 light-years from Earth in the constellation Virgo. The exoplanet is 0.06 astronomical units from its star and orbits it once in almost six days. Early observations of it helped to identify helium in its atmosphere, and also to determine that the exoplanet may be super-Neptune.