Gliese 832 (Gl 832 or GJ 832) is a

red dwarf ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...

spectral type In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

M2V in the southern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Grus. The

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

of 8.66 means that it is too faint to be seen with the naked eye. It is located relatively close to the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

, at a distance of 16.2 light years and has a high

proper motion Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more dista ...

of 818.93 milliarcseconds per year. Gliese 832 has just under half the mass and radius of the Sun. Its estimated rotation period is a relatively leisurely 46 days. The star is roughly 9.5 billion years old. This star achieved

perihelion An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

some 52,920 years ago when it came within an estimated of the Sun. Gliese 832 emits X-rays. 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.

Planetary system

Gliese 832 hosts two known planets. In September 2008, it was announced that a

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...

-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 Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, the Milky Way. Histor ...

perturbation on its star of at least 0.95

milliarcsecond A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...

s 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. The orbital solution of the planet was refined in 2011. In 2014, a second planet

Gliese 832 c Gliese 832 c (also known as Gl 832 c or GJ 832 c) was a candidate exoplanet located 16.2 light-years (4.97 parsecs) away in the constellation of Grus, orbiting the star Gliese 832, a red dwarf. The existence of the planet was refuted in 202 ...

was discovered by astronomers at the University of New South Wales. This one is believed to be of super-Earth mass and has since been given the scientific name

. It was announced to orbit in the optimistic

habitable zone In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.J. F. Kas ...

but outside the conservative habitable zone of its parent star. 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. The existence of the planet was disputed in 2022 though. The region between Gliese 832 b and

is a zone where additional planets are possible.

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.

Notes

References

{{DEFAULTSORT:Gliese 832 Local Bubble M-type main-sequence stars 204961 106440 Grus (constellation) CD-49 13515 J21333397-4900323 Planetary systems with one confirmed planet TIC objects

Planetary system

Search for cometary disc

See also

Notes

References