A population of unbound planets between stars, with masses ranging from Lunar to Jovian masses, was indirectly detected, for the first time, by astrophysicists from the University of Oklahoma in 2018, in the lensing galaxy that lenses quasar RX J1131-1231 by microlensing.
[9][10] A team of scientists has used gravitational microlensing to come up with a tentative detection of an extragalactic exoplanet in Andromeda, the Milky Way's nearest large galactic neighbor.
The lensing pattern fits a star with a smaller companion, PA-99-N2, weighing just around 6.34 times the mass of Jupiter.
[13] In September 2020, the detection of a candidate planet orbiting the high-mass X-ray binary M51-ULS-1 in the Whirlpool Galaxy was announced.
[18] The bright giant star BD+20 2457 was proposed to host two super-Jupiter planets or brown dwarfs, although the claimed planetary system is not dynamically stable.
[23] If it had been real, the Jupiter-like planet would have been particularly interesting, orbiting a star nearing the end of its life and seemingly about to be engulfed by it, potentially providing an observational model for the fate of our own planetary system in the distant future (cf.