Astronomy:OGLE-2005-BLG-390L

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Short description: Star in the constellation Scorpius
OGLE-2005-BLG-390L
OGLE-2005-BLG-390Lb finder.png
OGLE-2005-BLG-390L's location in the night sky.
Observation data
Equinox J2000.0]] (ICRS)
Constellation Scorpius
Right ascension  17h 54m 19.2s[1]
Declination −30° 22′ 38″[1]
Apparent magnitude (V) 15.7
Characteristics
Spectral type M4[1]
Astrometry
Distance21,500 ±3300 ly
(6,600 ±1,000 pc)
Details
Mass0.22 M
Other designations
EWS 2005-BUL-390, EWS 2005-BLG-390[1]
Database references
SIMBADdata
Extrasolar Planets
Encyclopaedia
data

OGLE-2005-BLG-390L is a star thought to be a spectral type M (a red dwarf; 95% probability, 4% probability it is a white dwarf, <1% probability it is a neutron star or black hole). This dim magnitude 16 galactic bulge star is located in the Scorpius constellation at a far distance of about 21,500 light years.[1]

Planetary system

Artist's impression of OGLE-2005-BLG-390Lb planet.

OGLE-2005-BLG-390L has one known planet, which was discovered using the technique of gravitational microlensing. Indications are that the planet is about five times Earth mass, orbiting at about 2.6 astronomical units from the parent star. The discovery was announced on January 25, 2006.[2] OGLE-2005-BLG-390Lb was once considered one of the smallest known extrasolar planets around a main sequence star, possibly rocky, with a mass around 5.5 times that of the Earth. The orbital radius (assuming a circular orbit) of the planet is 2.6 AU, however the orbital elements are unknown. Based on its low mass and estimated temperature of around 50 K, the planet is thought to consist mainly of ices, like Pluto or Uranus, rather than being a Jupiter-like gas giant.[2]

The OGLE-2005-BLG-390L planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 5.5 M 2.6 ~3500

See also

References

  1. 1.0 1.1 1.2 1.3 1.4 "SIMBAD query result: NAME OGLE 2005-BLG-390 -- (Micro)Lensing Event". Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=EWS+2005-BLG-390. 
  2. 2.0 2.1 Beaulieu, J.-P. et al. (January 2006). "Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing". Nature 439 (7075): 437–440. doi:10.1038/nature04441. PMID 16437108. Bibcode2006Natur.439..437B. 

External links

Coordinates: Sky map 17h 54m 19s, −30° 22′ 38″