MOA-2007-BLG-192Lb

MOA-2007-BLG-192Lb, occasionally shortened to MOA-192 b,^[2] is an extrasolar planet approximately 7,000 light-years away in the constellation of Sagittarius. The planet was discovered orbiting the low-mass star MOA-2007-BLG-192L. It was found when it caused a gravitational microlensing event on May 24, 2007, which was detected as part of the MOA-II microlensing survey at the Mount John University Observatory in New Zealand.^[3]

MOA-2007-BLG-192Lb

An artist's impression of MOA-2007-BLG-192Lb orbiting its primary.
Discovery
Discovered by	Bennett et al.
Discovery site	Mount John University Observatory,  New Zealand
Discovery date	30 May 2008
Detection method	Gravitational microlensing
Orbital characteristics
Semi-major axis	2.02±0.44 AU[1]
Star	MOA-2007-BLG-192L
Physical characteristics
Mass	12.49+65.47 −8.03 ME (likely between 3 and 12 ME)[1]

The mass of the planet is not well-known. It is anything between 2.75 and 105 Earth masses (M_E), although it is more likely to be between 3 and 12 M_E. The mass range also means that the planet's classification varies, from a Super-Earth to a Sub-Saturn. It is located at 2.02 astronomical units from its host star.^[1]

Host star

MOA-2007-BLG-192L

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Sagittarius[a]
Right ascension	18h 18m 03.8s[1]
Declination	−27° 09′ 00.27″[1]
Characteristics
Evolutionary stage	Red dwarf
Spectral type	M[1]
Astrometry
Distance	7040±980 ly (2160±300 pc)[1]
Details
Mass	0.28±0.04[1] M☉
Database references
SIMBAD	data

MOA-2007-BLG-192L is a red dwarf star, one of the smallest and least massive type of stars, as well as one of the most numerous in the Milky Way.^[4] It was initially estimated to have a mass 6% the mass of the Sun, which would probably be too low to sustain nuclear fusion at its core, making it a dimly glowing brown dwarf.^[5] However, this mass was based on an erroneous parallax, and a further analysis suggest a higher mass of 0.24 M_☉. This would make it a red dwarf.^[1]

Both MOA-2007-BLG-192L and its planet are located at a distance of 2,160 pc (7,000 ly) from Earth,^[1] in the direction of the constellation Sagittarius.^[a]

Notes

1. Obtained with a right ascension of 18^h 18^m 03.8^s and a declination of −27° 09′ 00.27″^[1] on this website.