Gliese 832

Gliese 832
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Grus
Right ascension 21h 33m 33.9752s
Declination -49° 00′ 32.422″
Apparent magnitude (V) 8.66[1]
Characteristics
Spectral type M1.5V
B−V color index 1.52[1]
Astrometry
Radial velocity (Rv) 18.0 km/s
Proper motion (μ) RA: -46.18[2] mas/yr
Dec.: -817.96[2] mas/yr
Parallax (π) 202.52 ± 1.33[2] mas
Distance 16.1 ± 0.1 ly
(4.94 ± 0.03 pc)
Details
Mass 0.45 ± 0.05[1] M☉
Radius 0.48[3] R☉
Surface gravity (log g) 4.7[1]
Luminosity (bolometric) 0.035[note 1] L☉
Temperature 3,620[4] K
Metallicity −0.31 ± 0.2[1]
Other designations
HD 204961, HIP 106440, LHS 3865
Database references
SIMBAD data
NStED data
Extrasolar Planets
Encyclopaedia		 data
Data sources:
Hipparcos Catalogue,
HD

Gliese 832 (Gl 832 or GJ 832) is a red dwarf star (spectrum M1.5V) in the constellation Grus. It is located relatively near our Sun, at a distance of 16.1 light years. The star is about half the mass and radius of the Sun.

Contents

Jupiter-like planet

In September 2008, it was announced that a Jupiter-like planet had been detected in a long-period, near-circular orbit around this star (false alarm probability thus far: a negligible 0.05%). It would induce an astrometric perturbation on its star of at least 0.95 milliarcseconds and is thus a good candidate for being detected by astrometric observations. Among currently-known exoplanets, it would have an angular distance from its star second only to Epsilon Eridani b, although direct imaging is problematic due to the star–planet contrast.[1]

The Gliese 832 system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity
b ≥0.64 ± 0.06 MJ 3.4 ± 0.4 3416 ± 131 0.12 ± 0.11

X-ray source

Gliese 832 emits X-rays.[5]

See also

Notes

  1. ^ From L=4πR2σTeff4, where L is the luminosity, R is the radius, Teff is the effective surface temperature and σ is the Stefan–Boltzmann constant.

References

  1. ^ a b c d e f Bailey, Jeremy et al. (2008). "A Jupiter-like Planet Orbiting the Nearby M Dwarf GJ832". The Astrophysical Journal 690 (1): 743–747. arXiv:0809.0172. Bibcode 2009ApJ...690..743B. doi:10.1088/0004-637X/690/1/743. 
  2. ^ a b c Perryman, M. A. C. et al. (1997), "The Hipparcos Catalogue", Astronomy & Astrophysics 323: L49–L52, Bibcode 1997A&A...323L..49P 
  3. ^ Johnson, H. M.; Wright, C. D. (1983). "Predicted infrared brightness of stars within 25 parsecs of the sun". Astrophysical Journal Supplement Series 53: 643–771. Bibcode 1983ApJS...53..643J. doi:10.1086/190905. 
  4. ^ Interpolated value from NStED, per:
    Bessell, M. S. (August 10-12, 1994). "The Bottom of the Main Sequence - and Beyond". In Christopher G. Tinney. Proceedings of the ESO Workshop. Garching, Germany: Springer-Verlag Berlin Heidelberg New York. Bibcode 1995bmsb.conf..123B. 
  5. ^ Schmitt, J.H.M.M.; Fleming, T.A.; Giampapa M.S. (September 1995). "The X-ray view of the low-mass stars in the solar neighborhood". Astrophysical Journal 450 (9): 392–400. Bibcode 1995ApJ...450..392S. doi:10.1086/176149. 

Coordinates: 21h 33m 33.9752s, −49° 00′ 32.422″

Stars of Grus
Bayer
Nearby
  • Gliese 832
  • GJ 4248