MOA-2007-BLG-192Lb
Terrestrial ice planet orbiting MOA-2007-BLG-192L
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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]
Observatory, New Zealand
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 |
| Gravitational microlensing | |
| Orbital characteristics | |
| 2.02±0.44 AU[1] | |
| Star | MOA-2007-BLG-192L |
| Physical characteristics | |
| Mass | 12.49+65.47 −8.03 M🜨 (likely between 3 and 12 M🜨)[1] |
The mass of the planet is not well known. It is anything between 2.75 and 105 Earth masses (M🜨), although it is more likely to be between 3 and 12 M🜨. 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
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| 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 0.28 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]