Kepler-1625 b

Kepler-1625b is a super-Jupiter exoplanet orbiting the Sun-like star Kepler-1625 about away. The large gas giant is approximately the same radius as Jupiter and orbits its star every 287.4 days. In 2017, hints of a Neptune-sized exomoon in orbit of the planet was found using photometric observations collected by the Kepler Mission. Further evidence for a Neptunian moon was found the following year using the Hubble Space Telescope, where two independent lines of evidence constrained the mass and radius to be Neptune-like. The mass-signature has been independently recovered by two other teams. However, the radius-signature was independently recovered by one of the teams but not the other. The original discovery team later showed that this latter study appears affected by systematic error sources that may influence their findings. Kepler-1625b is a Jovian-sized gas giant, a type of planet several times greater in radius than Earth and mostly composed of hydrogen and helium. It is 11.4 times Earth's radius, approximately equal to that of the planet Jupiter. However, it is up to 11.6 times more massive (about 3,700 Earth masses), based on radial velocity observations. This puts it just below the deuterium-fusing limit, which is around 13 Jupiter masses. Any more massive and Kepler-1625b would be a brown dwarf. However, this mass value only corresponds to an 3-sigma upper limit and the mass of the planet remains undetected at this time. Unlike the gas giants in our Solar System, Kepler-1625b orbits much closer, slightly closer than the orbital radius as the Earth around the Sun. The planet takes to orbit Kepler-1625, as a result of the star's slightly greater mass than the Sun. Kepler-1625b receives 2.6 times more insolation than the Earth, meaning it lies at the inner edge of the habitable zone. However, as the planet has likely no solid surface, bodies of liquid water are impossible. Kepler-1625b I In July 2017, researchers found signs of a Neptune-sized exomoon (a moon in another solar system) orbiting Kepler-1625b using archival Kepler Mission data.