Gliese 832

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Gliese 832
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Grus
Right ascension 21h 33m 33.975s[1]
Declination −49° 00′ 32.42″[1]
Apparent magnitude (V) 8.66[2]
Characteristics
Spectral type M1.5V
B−V color index 1.52[2]
Astrometry
Radial velocity (Rv) 18.0 km/s
Proper motion (μ) RA: −46.05 ± 0.95[1] mas/yr
Dec.: −817.63 ± 0.59[1] mas/yr
Parallax (π) 201.87 ± 1.01[1] mas
Distance 16.16 ± 0.08 ly
(4.95 ± 0.02 pc)
Details
Mass 0.45 ± 0.05[2] M
Radius 0.48[3] R
Luminosity (bolometric) 0.035[note 1] L
Surface gravity (log g) 4.7[2] cgs
Temperature 3,620[4] K
Metallicity −0.31 ± 0.2[2]
Other designations
HD 204961, HIP 106440, LHS 3865
Database references
SIMBAD data
Exoplanet Archive data
Extrasolar Planets
Encyclopaedia
data
Data sources:
Hipparcos Catalogue,
HD

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

In 2014, Gliese 832 was announced to be hosting the closest potentially habitable Earth-mass range exoplanet to our solar system.[5]

Planetary system[edit]

Gliese 832 hosts two known planets.

Discovery of Jupiter mass planet[edit]

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.[2]

Discovery of Gliese 832 c (super-Earth mass planet) in habitable zone[edit]

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[5] and has since been given the scientific name Gliese 832 c.[5] It was announced to orbit in the optimistic habitable zone but outside the conservative habitable zone of its parent star.[6]

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.[5]

Search for cometary disc[edit]

If this system has a comet disc, it is undetectable "brighter than the fractional dust luminosity 10−5" of a recent Herschel study.[7]

The Gliese 832 planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
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

X-ray source[edit]

Gliese 832 emits X-rays.[8]

See also[edit]

Notes[edit]

  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[edit]

  1. ^ a b c d e 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
  2. ^ a b c d e f 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. 
  3. ^ 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. 
  4. ^ 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. 
  5. ^ a b c d e f g "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
  6. ^ 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. 
  7. ^ 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. 
  8. ^ 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. 


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