MOA-2011-BLG-262L

MOA-2011-BLG-262L

Characteristics
Apparent magnitude (K)	22.3
Observation data Epoch J2000      Equinox J2000
Constellation	Sagittarius[1]
Right ascension	18^h 00^m 23.48^s[2]
Declination	−31° 14′ 42.93″[2]
Astrometry
Distance	24,400±3,000 ly (7,490±910 pc)[3]
Details[3]
Mass	0.193±0.029 M☉
Database references
SIMBAD	data

MOA-2011-BLG-262L is a red dwarf with an orbiting exoplanet, both detected through the gravitational microlensing event MOA-2011-BLG-262.[3] It was once believed to be either an exoplanet with 3.2 times the mass of Jupiter and a exomoon with 0.47 times Earth's mass or a red dwarf with a mass of 0.11 solar masses orbited by a ~17 M_🜨 planet,[2][4] but the latter scenario was confirmed in 2024 based on observations of the host star by the Keck telescope, 10 years after the ending of the microlensing event.[3]

An artist's rendition of the system as a rogue planet with a moon (left) and a star with a planet (right); since 2024, the scenario on the right has been confirmed as the actual system

The system is located 24,400 light-years from Earth, in the constellation Sagittarius.[1] The host star is a red dwarf, with 19% the Sun's mass and a faint apparent magnitude of 22.3 in the K-band. It has a transverse velocity of 541.3±65.75 km/s, the highest ever found for any star with a known exoplanet.[3]

The MOA-2011-BLG-262L planetary system[3]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	28.92±4.75 M🜨	0.98+0.56 −0.20	—	—	—	—

References

1. "Finding the constellation which contains given sky coordinates". djm.cc. 2 August 2008.
2. Bennett, D.P.; Batista, V.; et al. (13 December 2013). "A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic Bulge". The Astrophysical Journal. 785 (2): 155. arXiv:1312.3951. Bibcode:2014ApJ...785..155B. doi:10.1088/0004-637X/785/2/155. S2CID 118327512.
3. Terry, Sean K.; Beaulieu, Jean-Philippe; Bennett, David P.; Bhattacharya, Aparna; Hulberg, Jon; Huston, Macy J.; Koshimoto, Naoki; Blackman, Joshua W.; Bond, Ian A. (2024-10-11). "A Candidate High-Velocity Exoplanet System in the Galactic Bulge". arXiv:2410.09147.
4. Clavin, Whitney (10 April 2014). "Faraway Moon or Faint Star? Possible Exomoon Found". NASA. Archived from the original on 12 April 2014. Retrieved 19 February 2023.