Gliese 687

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Template:Short description Template:Sky

Gliese 687
File:Gliese 687.jpg
Gliese 687 is the small orange star located in the center of the above image.
Observation data
Epoch J2000      Equinox J2000
Constellation Draco
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) 9.15[2]
Characteristics
Spectral type M3.5 V[3]
U−B Template:Engvar 1.06
B−V Template:Engvar 1.49
Astrometry
Radial velocity (Rv)Script error: No such module "val".[1] km/s
Proper motion (μ) RA: –320.675 mas/yr[1]
Dec.: –1269.893 mas/yr[1]
Parallax (π)219.7898±0.0210 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)10.87
Details
MassScript error: No such module "val".[4] Template:Solar mass
RadiusScript error: No such module "val".[5] Template:Solar radius
LuminosityScript error: No such module "val".[5] Template:Solar luminosity
Surface gravity (log g)4.66[6] cgs
TemperatureScript error: No such module "val".[5] K
Metallicity [Fe/H]+0.11 ± 0.20[6] dex
RotationScript error: No such module "val".[7]
Rotational velocity (v sin i)<2.8[8] km/s
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Template:Odlist[2]
Database references
SIMBADdata
Exoplanet Archivedata
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Gliese 687, or GJ 687 (Gliese–Jahreiß 687) is a red dwarf in the constellation Draco. This is one of the closest stars to the Sun and lies at a distance of Script error: No such module "convert".. Even though it is close by, it has an apparent magnitude of about 9, so it can only be seen through a moderately sized telescope. Gliese 687 has a high proper motion, advancing 1.304 arcseconds per year across the sky. It has a net relative velocity of about 39 km/s.[2] It is known to have a Neptune-mass planet.[7] Old books and articles refer to it as Argelander Oeltzen 17415.[9]

Properties

Gliese 687 has about 40% of the Sun's mass and nearly 50% of the Sun's radius. Compared to the Sun, it has a slightly higher proportion of elements with higher atomic numbers than helium.[6] It seems to rotate every 60 days and exhibit some chromospheric activity.

It displays no excess of infrared radiation that would indicate orbiting dust.[10]

Gliese 687 is a solitary red dwarf that emits X-rays.[11]

Planetary system

In 2014, Gliese 687 was discovered to have a planet, Gliese 687 b, with a minimum mass of 18.394 Earth masses (which makes it comparable to Neptune), an orbital period of 38.14 days, a low orbital eccentricity and inside the habitable zone.[7] Another Neptune-mass planet candidate was discovered in 2020, in a further out and much colder orbit.[4]

Template:OrbitboxPlanet begin Template:OrbitboxPlanet Template:OrbitboxPlanet

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See also

References

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External links

Template:Nearest systems Template:Stars of Draco