Epoch J2000.0 Equinox J2000.0
|Right ascension||21h 33m 33.975s|
|Declination||−49° 00′ 32.42″|
|Apparent magnitude (V)||8.66|
|B−V color index||1.52|
|Radial velocity (Rv)||18.0 km/s|
|Proper motion (μ)||RA: −46.05 ± 0.95 mas/yr
Dec.: −817.63 ± 0.59 mas/yr
|Parallax (π)||201.87 ± 1.01 mas|
|Distance||16.16 ± 0.08 ly
(4.95 ± 0.02 pc)
|Mass||0.45 ± 0.05 M☉|
|Luminosity (bolometric)||0.035[note 1] L☉|
|Surface gravity (log g)||4.7 cgs|
|Metallicity||−0.31 ± 0.2|
Gliese 832 (Gl 832 or GJ 832) is a red dwarf (spectrum M1.5V) in the constellation Grus. It is located relatively close to the Sun, at a distance of 16.1 light years. Gliese 832 has about half the mass and radius of the Sun.
In 2014, Gliese 832 was announced to be hosting the closest potentially habitable Earth-mass range exoplanet to our solar system.
Gliese 832 hosts two known planets.
Discovery of Jupiter mass planet
In September 2008, it was announced that a Jupiter-like planet, now designated as Gliese 832 b, 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. Despite its relatively large angular distance, direct imaging is problematic due to the star–planet contrast.
Discovery of Gliese 832 c (super-Earth mass planet) in habitable zone
In 2014, a second planet was discovered by astronomers at the University of New South Wales. This one is believed to be of super-Earth mass and has since been given the scientific name Gliese 832 c. It was announced to orbit in the optimistic habitable zone but outside the conservative habitable zone of its parent star.
The planet is believed to be in, or very close to, the right distance from its sun to allow liquid water to exist on its surface.
Search for cometary disc
If this system has a comet disc, it is undetectable "brighter than the fractional dust luminosity 10−5" of a recent Herschel study.
(in order from star)
|c||≥5.4±1 M⊕||0.162±0-017||35.68±0.03||0.18 ± 0.13||—||—|
|b||≥0.64 ± 0.06 MJ||3.4 ± 0.4||3416 ± 131||0.12 ± 0.11||—||—|
Gliese 832 emits X-rays.
- 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.
- van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
- Bailey, J.; Butler, R. P.; Tinney, C. G.; Jones, H. R. A.; O'Toole, S.; Carter, B. D.; Marcy, G. W. (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.
- Johnson, H. M.; Wright, C. D. (1983). "Predicted infrared brightness of stars within 25 parsecs of the sun". The Astrophysical Journal Supplement Series 53: 643–771. Bibcode:1983ApJS...53..643J. doi:10.1086/190905.
- Interpolated value from NASA Exoplanet Archive, per: Bessell, M. S. (1995). "The Temperature Scale for Cool Dwarfs". In Tinney, C. G. The Bottom of the Main Sequence - and Beyond, Proceedings of the ESO Workshop. Springer-Verlag. p. 123. Bibcode:1995bmsb.conf..123B.
- "Nearby Alien Planet May Be Capable of Supporting Life", Mike Wall, Space.com, June 25, 2014, http://www.space.com/26357-exoplanet-habitable-zone-gliese-832c.html
- Wittenmyer, R.A.; Tuomi, M.; Butler, R.P.; Jones, H. R. A.; O'Anglada-Escude, G.; Horner, J.; Tinney, C.G.; Marshall, J.P.; Carter, B.D. et al. (2014). GJ 832c: A super-earth in the habitable zone 1406. p. 5587. arXiv:1406.5587. Bibcode:2014arXiv1406.5587W.
- B. C. Matthews; forthcoming study promised in Lestrade, J.-F.; et al.; Sibthorpe, B.; Kennedy, G. M.; Wyatt, M. C.; Bryden, G.; Greaves, J. S.; Thilliez, E.; Moro-Martín, A.; Booth, M.; Dent, W. R. F.; Duchêne, G.; Harvey, P. M.; Horner, J.; Kalas, P.; Kavelaars, J. J.; Phillips, N. M.; Rodriguez, D. R.; Su, K. Y. L.; Wilner, D. J. (2012). "A DEBRIS Disk Around The Planet Hosting M-star GJ581 Spatially Resolved with Herschel". Astronomy and Astrophysics 548: A86. arXiv:1211.4898. Bibcode:2012A&A...548A..86L. doi:10.1051/0004-6361/201220325.
- Schmitt, J. H. M. M.; Fleming, T. A.; Giampapa, M. S. (1995). "The X-ray view of the low-mass stars in the solar neighborhood". The Astrophysical Journal 450 (9): 392–400. Bibcode:1995ApJ...450..392S. doi:10.1086/176149.