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Gliese 832 (Gl 832 or GJ 832) is a red dwarf of spectral type M2V in the southern constellation Grus.[10] 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 818.93 milliarcseconds[11] per year.[1] Gliese 832 has just under half the mass and radius of the Sun.[10] Its estimated rotation period is a relatively leisurely 46 days.[3] The star is roughly 9.5 billion years old.[8]

Gliese 832

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Grus
Right ascension	21h 33m 33.9750s[1]
Declination	−49° 00′ 32.4035″[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)	18.0 km/s
Proper motion (μ)	RA: −45.834±0.071[1] mas/yr Dec.: −816.604±0.064[1] mas/yr
Parallax (π)	201.3252 ± 0.0237 mas[4]
Distance	16.200 ± 0.002 ly (4.9671 ± 0.0006 pc)
Absolute magnitude (MV)	10.19[2]
Details
Mass	0.441 ± 0.011[5] M☉
Radius	0.442 ± 0.018[5] R☉
Luminosity (bolometric)	0.0276 ± 0.0009 [5] L☉
Luminosity (visual, LV)	0.007[note 1] L☉
Surface gravity (log g)	4.7[2] cgs
Temperature	3,539+79 −74[5] K
Metallicity [Fe/H]	−0.06 ± 0.04[6] dex
Rotation	37.5+1.4 −1.5 d[7]
Age	9.24[8] Gyr
Other designations
CD-49°13515, HD 204961, HIP 106440, LHS 3685, PLX 5190[9]
Database references
SIMBAD	The star
	planet c
	planet b
Exoplanet Archive	data
Extrasolar Planets Encyclopaedia	data
Data sources:
Hipparcos Catalogue, HD
Gliese 832 Location of Gliese 832 in the constellation Grus

This star achieved perihelion some 52,920 years ago when it came within an estimated 15.71 ly (4.817 pc) of the Sun.[11]

Gliese 832 emits X-rays.[12] 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.[13]

Planetary system

Gliese 832 hosts two known planets.

The Gliese 832 planetary system[14]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
c (disputed[7])	≥5.4±1 M🜨	0.162±0-017	35.68±0.03	0.18 ± 0.13	—	—
b	≥0.62 MJ	3.46	3507±181	0.08±0.05	—	—

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] The orbital solution of the planet was refined in 2011.[14]

In 2014, a second planet Gliese 832 c was discovered by astronomers at the University of New South Wales. This one is believed to be of super-Earth mass[10] and has since been given the scientific name Gliese 832 c.[10] It was announced to orbit in the optimistic habitable zone but outside the conservative habitable zone of its parent star.[15] The planet Gliese 832 c is believed to be in, or very close to, the right distance from its sun to allow liquid water to exist on its surface.[10] The existence of the planet was disputed in 2022 though.[7]

The region between Gliese 832 b and Gliese 832 c is a zone where additional planets are possible.[16]

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.[17]

See also

• List of nearest stars
• List of extrasolar planets

Notes

References

На других языках

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[de] Gliese 832

Gliese 832 (auch Gl 832 oder GJ 832) ist ein Roter Zwerg der Spektralklasse M1.5V im Sternbild Kranich.[5] Mit 16,2 Lichtjahren Entfernung befindet er sich in relativer Nähe zur Sonne.[5] Gliese 832 hat in etwa die Hälfte der Masse und des Radius der Sonne.[5] Der Stern emittiert außerdem Röntgenstrahlung.[6]

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- [en] Gliese 832

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[es] Gliese 832

Gliese 832 (GJ 832)[1] es una estrella en la constelación de Grus (La Grulla), situada al este de α Indi. De magnitud aparente +8,67, es demasiado tenue para ser observada a simple vista. Se encuentra a 16,1 años luz de distancia del sistema solar. Se sabe de la existencia de 2 planetas extrasolares en órbita alrededor de esta estrella.

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[ru] Глизе 832

Глизе 832 (лат. Gliese 832) — звезда в созвездии Журавля. Находится на расстоянии около 16,1 световых лет от Солнца. Вокруг звезды обращается, как минимум, две планеты.

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