Gliese 832

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
Distance16.16 ± 0.08 ly
(4.95 ± 0.02 pc)
Absolute magnitude (MV)10.19[2]
Details
Mass0.45 ± 0.05[2] M☉
Radius0.48[3] R☉
Luminosity (bolometric)0.035[note 1] L☉
Luminosity (visual, LV)0.007[note 2] L☉
Surface gravity (log g)4.7[2] cgs
Temperature3,620[6] K
Metallicity−0.31 ± 0.2[2]
Other designations
HD 204961, HIP 106440, LHS 3865, PLX 5190
Database references
SIMBADstar
planet c
planet b
Exoplanet Archivedata
Extrasolar Planets
Encyclopaedia		data
Data sources:
Hipparcos Catalogue,
HD

Gliese 832 (Gl 832 or GJ 832) is a red dwarf of spectral type M1.5V in the constellation Grus.[7] It is located relatively close to the Sun, at a distance of 16.1 light years.[7] Gliese 832 has about half the mass and radius of the Sun.[7]

In 2014, Gliese 832 was announced to be hosting the closest potentially habitable Earth-mass-range exoplanet to the Solar System.[7]

Distance

Gliese 832 distance estimates

Source Parallax, mas Distance, pc Distance, ly Distance, Pm Ref.
Woolley et al. (1970) 214±7 4.67+0.16
−0.15		 15.2±0.5 144.2+4.9
−4.6		 [8]
Gliese & Jahreiß (1991) 215.0±6.1 4.65+0.14
−0.13		 15.2±0.4 143.5+4.2
−4		 [9]
van Altena et al. (1995) 213.9±8.8 4.68+0.2
−0.18		 15.2+0.7
−0.6		 144.3+6.2
−5.7		 [10]
Perryman et al. (1997) (Hipparcos) 202.53±1.33 4.94±0.03 16.1±0.11 152.4±1 [11]
Perryman et al. (1997) (Tycho) 229.00±15.10 4.37+0.31
−0.27		 14.2+1
−0.9		 134.7+9.5
−8.3		 [12]
van Leeuwen (2007) 201.87±1.01 4.954±0.025 16.16±0.08 152.9±0.8 [1]
RECONS TOP100 (2012) 202.03±1.00[note 3] 4.95+0.025
−0.024		 16.14±0.08 152.7±0.8 [13]

Non-trigonometric distance estimates are marked in italic. The most precise estimate is marked in bold.

Planetary 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.[2]

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[7] and has since been given the scientific name Gliese 832 c.[7] It was announced to orbit in the optimistic habitable zone but outside the conservative habitable zone of its parent star.[14]

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.[7]

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.[15]

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

Gliese 832 emits X-rays.[16]

See also

Notes

  1. ↑ Using the absolute visual magnitude of Gliese 832 \scriptstyle M_{V_{\ast}}=10.19 with a bolometric correction of \scriptstyle BC=-1.821[4] the bolometric magnitude can be calculated as \scriptstyle M_{bol_{\ast}}=8.369, the bolometric magnitude of the Sun \scriptstyle M_{bol_{\odot}}=4.73,[5] and so therefore the bolometric luminosity can be calculated by \scriptstyle \frac{L_{bol_{\ast}}}{L_{bol_{\odot}}}=10^{0.4\left(M_{bol_{\odot}} - M_{bol_{\ast}}\right)}
  2. ↑ Using the absolute visual magnitude of Gliese 832 \scriptstyle M_{V_{\ast}}=10.19 and the absolute visual magnitude of the Sun \scriptstyle M_{V_{\odot}}=4.83, the visual luminosity can be calculated by \scriptstyle \frac{L_{V_{\ast}}}{L_{V_{\odot}}}=10^{0.4\left(M_{V_{\odot}} - M_{V_{\ast}}\right)}
  3. ↑ Weighted parallax based on parallaxes from van Altena et al. (1995) and van Leeuwen (2007).

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen F. (2007). "HIP 106440". Validation of the new Hipparcos reduction. Retrieved 2014-11-22.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 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. ↑ Flower, Phillip J. (September 1996). "Transformations from Theoretical Hertzsprung-Russell Diagrams to Color-Magnitude Diagrams: Effective Temperatures, B-V Colors, and Bolometric Corrections". The Astrophysical Journal 469: 355. Bibcode:1996ApJ...469..355F. doi:10.1086/177785.
  5. ↑ Torres, Guillermo (November 2010). "On the Use of Empirical Bolometric Corrections for Stars". The Astronomical Journal 140 (5): 1158–1162. arXiv:1008.3913. Bibcode:2010AJ....140.1158T. doi:10.1088/0004-6256/140/5/1158. Lay summary.
  6. ↑ 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.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 "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
  8. ↑ Woolley R.; Epps E. A.; Penston M. J.; Pocock S. B. (1970). "Woolley 832". Catalogue of stars within 25 parsecs of the Sun. Retrieved 2014-11-22.
  9. ↑ Gliese, W. and Jahreiß, H. (1991). "Gl 832". Preliminary Version of the Third Catalogue of Nearby Stars. Retrieved 2014-11-22.
  10. ↑ Van Altena W. F., Lee J. T., Hoffleit E. D. (1995). "GCTP 5190". The General Catalogue of Trigonometric Stellar Parallaxes (Fourth ed.). Retrieved 2014-11-22.
  11. ↑ Perryman et al. (1997). "HIP 106440". The Hipparcos and Tycho Catalogues. Retrieved 2014-11-22.
  12. ↑ Perryman et al. (1997). "HIP 106440". The Hipparcos and Tycho Catalogues. Retrieved 2014-11-22.
  13. ↑ "RECONS TOP100". THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars). 2012. Retrieved 2014-11-22.
  14. ↑ 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:2014ApJ...791..114W. doi:10.1088/0004-637X/791/2/114.
  15. ↑ B. C. Matthews; forthcoming study promised in Lestrade, J.-F.; 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. et al. (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.
  16. ↑ 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: 21h 33m 33.9752s, −49° 00′ 32.422″