Kepler-1625b

Kepler-1625b is a super-Jupiter exoplanet orbiting the Sun-like star Kepler-1625 about 2,500 parsecs (8,200 light-years) away in the constellation of Cygnus. 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.