Astronomy:Gliese 832
  Gliese 832 Location of Gliese 832 in the constellation Grus | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Grus |
| Right ascension | 21h 33m 33.97512s[1] |
| Declination | −49° 00′ 32.3994″[1] |
| Apparent magnitude (V) | 8.66[2] |
| Characteristics | |
| Evolutionary stage | main-sequence star |
| Spectral type | M2V[3] |
| B−V color index | 1.52[2] |
| Astrometry | |
| Radial velocity (Rv) | 12.72±0.13[1] km/s |
| Proper motion (μ) | RA: −45.917[1] mas/yr Dec.: −816.875[1] mas/yr |
| Parallax (π) | 201.3252 ± 0.0237[1] mas |
| Distance | 16.200 ± 0.002 ly (4.9671 ± 0.0006 pc) |
| Absolute magnitude (MV) | 10.19[2] |
| Details | |
| Mass | 0.441 ± 0.011[4] M☉ |
| Radius | 0.442 ± 0.018[4] R☉ |
| Luminosity (bolometric) | 0.0276 ± 0.0009 [4] L☉ |
| Luminosity (visual, LV) | 0.007[note 1] L☉ |
| Surface gravity (log g) | 4.7[2] cgs |
| Temperature | 3,539+79 −74[4] K |
| Metallicity [Fe/H] | −0.06 ± 0.04[5] dex |
| Rotation | 37.5+1.4 −1.5 d[6] |
| Age | 6±1.5[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | The star |
| planet c | |
| planet b | |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
| Data sources: | |
| Hipparcos Catalogue, HD | |
Gliese 832 (Gl 832 or GJ 832) is a red dwarf of spectral type M2V in the southern constellation Grus.[8] The apparent visual magnitude of 8.66[2] means that it is too faint to be seen with the naked eye. It is located relatively close to the Sun, at a distance of 16.2 light years[1] and has a high proper motion of 818.16 milliarcseconds per year.[1] Gliese 832 has just under half the mass and radius of the Sun.[8] Its estimated rotation period is a relatively leisurely 46 days.[3] The star is roughly 6 billion years old.[6]
This star achieved perihelion some 52,920 years ago when it came within an estimated 15.71 ly (4.817 pc) of the Sun.[9]
Gliese 832 emits X-rays.[10] Despite the strong flare activity, Gliese 832 is producing on average less ionizing radiation than the Sun. Only at extremely short radiation wavelengths (<50nm) does its radiation intensity rise above the level of quiet Sun, but does not reach levels typical for active Sun.[11]
Planetary system
Gliese 832 hosts one known planet, with a second planet having been refuted in 2022.[6]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.8+0.12 −0.11 MJ |
3.53+0.15 −0.16 |
9.88+0.34 −0.33 |
0.069+0.026 −0.027 |
54.9+6.6 −4.9 or 125.1+4.9 −6.6° |
— |
Gliese 832 b
In September 2008, it was announced that a Jupiter-like planet, designated Gliese 832 b, had been detected in a long-period, near-circular orbit around this star, with a false alarm probability of 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] The orbital solution of the planet was refined in 2011.[13] In 2023, an astrometric detection of the planet was announced, determining its inclination and revealing a true mass 80% the mass of Jupiter.[12]
Gliese 832 c
Gliese 832 c was believed to be of super-Earth mass.[8] It was announced to orbit in the optimistic habitable zone but outside the conservative habitable zone of its parent star.[14] The planet Gliese 832 c was believed to be in, or very close to, the right distance from its sun to allow liquid water to exist on its surface.[8] However, doubts were raised about the existence of planet c by a 2015 study, which found that its orbital period is close to the stellar rotation period.[3] The existence of the planet was refuted in 2022, when a study found that the radial velocity signal shows characteristics of a signal originating from stellar activity, and not from a planet.[6]
The region between Gliese 832 b and where Gliese 832 c would be is a zone where additional planets are possible.[15]
Search for cometary disc
If this system has a comet disc, it is not "brighter than the fractional dust luminosity 10−5" according to a 2012 Herschel study.[16]
See also
- List of nearest stars
- List of extrasolar planets
Notes
- ↑ Using the absolute visual magnitude of Gliese 832 [math]\displaystyle{ \scriptstyle M_{V_{\ast}}=10.19 }[/math] and the absolute visual magnitude of the Sun [math]\displaystyle{ \scriptstyle M_{V_{\odot}}=4.83 }[/math], the visual luminosity can be calculated by [math]\displaystyle{ \scriptstyle \frac{L_{V_{\ast}}}{L_{V_{\odot}}}=10^{0.4\left(M_{V_{\odot}} - M_{V_{\ast}}\right)} }[/math]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Bailey, J.; Butler, R. P.; Tinney, C. G.; Jones, H. R. A.; O'Toole, S.; Carter, B. D.; Marcy, G. W. (2009). "A Jupiter-like Planet Orbiting the Nearby M Dwarf GJ832". The Astrophysical Journal 690 (1): 743–747. doi:10.1088/0004-637X/690/1/743. Bibcode: 2009ApJ...690..743B.
- ↑ 3.0 3.1 3.2 Suárez Mascareño, A. et al. (September 2015), "Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators", Monthly Notices of the Royal Astronomical Society 452 (3): 2745–2756, doi:10.1093/mnras/stv1441, Bibcode: 2015MNRAS.452.2745S.
- ↑ 4.0 4.1 4.2 4.3 Pineda, J. Sebastian; Youngblood, Allison; France, Kevin (September 2021). "The M-dwarf Ultraviolet Spectroscopic Sample. I. Determining Stellar Parameters for Field Stars". The Astrophysical Journal 918 (1): 23. doi:10.3847/1538-4357/ac0aea. 40. Bibcode: 2021ApJ...918...40P.
- ↑ Lindgren, Sara; Heiter, Ulrike (2017). "Metallicity determination of M dwarfs. Expanded parameter range in metallicity and effective temperature". Astronomy and Astrophysics 604: A97. doi:10.1051/0004-6361/201730715. Bibcode: 2017A&A...604A..97L. https://www.aanda.org/articles/aa/full_html/2017/08/aa30715-17/aa30715-17.html.
- ↑ 6.0 6.1 6.2 6.3 6.4 Gorrini, P. et al. (August 2022). "Detailed stellar activity analysis and modelling of GJ 832: Reassessment of the putative habitable zone planet GJ 832c". Astronomy & Astrophysics 664: A64. doi:10.1051/0004-6361/202243063. Bibcode: 2022A&A...664A..64G.
- ↑ "Gliese 832". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Gliese+832.
- ↑ 8.0 8.1 8.2 8.3 "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
- ↑ Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics 575: 13, doi:10.1051/0004-6361/201425221, A35, Bibcode: 2015A&A...575A..35B.
- ↑ 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. doi:10.1086/176149. Bibcode: 1995ApJ...450..392S.
- ↑ Fontenla, J. M.; Linsky, Jeffrey L.; Garrison, Jesse; France, Kevin; Buccino, A.; Mauas, Pablo; Vietes, Mariela; Walkowicz, Lucianne M. (2016). "Semi-Empirical Modeling of the Photosphere, Chromopshere, Transition Region, and Corona of the M-Dwarf Host Star Gj 832". The Astrophysical Journal 830 (2): 154. doi:10.3847/0004-637X/830/2/154. Bibcode: 2016ApJ...830..154F.
- ↑ 12.0 12.1 Xiao, Guang-Yao et al. (March 2023). "The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements". Research in Astronomy and Astrophysics 23 (5). doi:10.1088/1674-4527/accb7e. Bibcode: 2023RAA....23e5022X.
- ↑ Bonfils, Xavier; Delfosse, Xavier; Udry, Stéphane; Forveille, Thierry; Mayor, Michel; Perrier, Christian; Bouchy, François; Gillon, Michaël et al. (2011). "The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample". Astronomy and Astrophysics 549: A109. doi:10.1051/0004-6361/201014704. Bibcode: 2013A&A...549A.109B.
- ↑ Wittenmyer, R.A.; Tuomi, M.; Butler, R.P.; Jones, H. R. A.; O'Anglada-Escude, G.; Horner, J.; Tinney, C.G.; Marshall, J.P. et al. (2014). "GJ 832c: A super-earth in the habitable zone". The Astrophysical Journal 1406 (2): 5587. doi:10.1088/0004-637X/791/2/114. Bibcode: 2014ApJ...791..114W.
- ↑ Satyal, S.; Griffith, J.; Musielak, Z. E. (2016), "Dynamics of a Probable Earth-mass Planet in GJ 832 System", The Astrophysical Journal 845 (2): 106, doi:10.3847/1538-4357/aa80e2
- ↑ B. C. Matthews; forthcoming study promised in Lestrade, J.-F.; Matthews, B. C.; Sibthorpe, B.; Kennedy, G. M.; Wyatt, M. C.; Bryden, G.; Greaves, J. S.; Thilliez, E. et al. (2012). "A DEBRIS Disk Around The Planet Hosting M-star GJ581 Spatially Resolved with Herschel". Astronomy and Astrophysics 548: A86. doi:10.1051/0004-6361/201220325. Bibcode: 2012A&A...548A..86L.
Coordinates: 
21h 33m 33.9752s, −49° 00′ 32.422″
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