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|---|---|
| Constellation | Grus |
| Right ascension | 21 33 33.975 |
| Declination | −49° 00′ 32.42″ |
| Apparent magnitude (V) | 8.66 |
| Characteristics | |
| Spectral type | M1.5V |
| B−V color index | 1.52 |
| Astrometry | |
| 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) |
| Details | |
| Mass | 0.45 ± 0.05 M☉ |
| Radius | 0.48 R☉ |
| Luminosity (bolometric) | 0.035 L☉ |
| Surface gravity (log g) | 4.7 cgs |
| Temperature | 3,620 K |
| Metallicity | −0.31 ± 0.2 |
| Other designations | |
| HD 204961, HIP 106440, LHS 3865 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Data sources: | |
| Hipparcos Catalogue, HD | |
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.
Planetary system
Gliese 832 hosts two known planets.
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. Despite its relatively large angular distance, direct imaging is problematic due to the star–planet contrast.
In 2014, a second super-Earth mass planet was announced to orbit in the optimistic habitable zone but outside the conservative habitable zone.
If this system has a comet disc, it is undetectable "brighter than the fractional dust luminosity 10" of a recent Herschel study.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | ≥5.4±1 M🜨 | — | 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.
See also
Notes
- From L = 4πRσTeff, where L is the luminosity, R is the radius, Teff is the effective surface temperature and σ is the Stefan–Boltzmann constant.
References
- ^ van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction" (PDF). 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. (ed.). The Bottom of the Main Sequence - and Beyond, Proceedings of the ESO Workshop. Springer-Verlag. p. 123. Bibcode:1995bmsb.conf..123B.
{{cite conference}}: Unknown parameter|booktitle=ignored (|book-title=suggested) (help) -
Wittenmyer, R.A.; Tuomi, M.; Butler, R.P.; Jones, H. R. A.; O'Anglada-Escude, G.; Horner, J.; Tinney, B.D.; Marshall; Carter (2014). "GJ 832c: A super-earth in the habitable zone". arXiv:1406.5587.
{{cite journal}}: Cite journal requires|journal=(help) -
B. C. Matthews; forthcoming study promised in Lestrade, J.-F.; 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.
{{cite journal}}: Explicit use of et al. in:|author2=(help) - 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.
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