Illustration of the planet Kepler 1625b and its proposed exomoon, transiting their star. Kepler 1625 is a Sun-like star some 4,000 light-years distant in Cygnus. It is about 80 percent of the radius of the Sun but about 8 percent more massive. The star has at least one known planet. Called Kepler 1625b, it is a large gas giant, up to 12 times the diameter of Jupiter and orbiting within the star's habitable zone. In 2018, astronomers reported that the planet might be orbited by a satellite - an exomoon - although this remains to be confirmed. The suspected moon is Neptunian in size, orbiting its planet at a distance of 20 times the planet's radius.