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Astronomers have discovered one of the most massive exoplanets, Gaia-4b, which has a mass of 11,8 Jupiters and orbits an orange dwarf star 244 light-years from Earth, questioning its nature as a gas giant.
The discovery was made while analyzing archival data from the Gaia space telescope, which shut down in January after 12 years of observations. Although Gaia-4b has a mass typical of planets, it is located in a system where such massive objects are not usually observed.
In addition to Gaia-4b, astronomers have also identified Gaia-5b – an object with a mass of 20,9 Jupiter masses, orbiting a red dwarf at a distance of 134 light years. It has been classified as a brown dwarf – an intermediate object between a planet and a star, as it has probably undergone gravitational compression of a gas cloud. The boundary between a planet and a brown dwarf remains debatable: the main criteria are the method of formation, mass (more than 13 Jupiter masses), and the ability to thermonuclearly fuse deuterium.
Despite the uncertainty of Gaia-4b's status, its discovery is an important step in understanding the formation of planetary systems. Further analysis of Gaia data may reveal even more unusual objects that will add to our understanding of planetary and stellar evolution.
