Gliese 809
Star in the constellation Cepheus
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Gliese 809 is a red dwarf star in the constellation Cepheus. A visual magnitude of 8.55 makes it too faint to see with the naked eye. It is part of the Gliese Catalogue of Nearby Stars and is located about 23 light-years (ly) from the Solar System. Gliese 809 has about 70.5% the radius of the Sun and 61.4%[3] of the Sun's mass. It has a metallicity of −0.06, which means that the abundance of elements other than hydrogen and helium is just 87.1% that of the Sun.
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Cepheus[1] |
| Right ascension | 20h 53m 19.78892s[2] |
| Declination | +62° 09′ 15.8173″[2] |
| Apparent magnitude (V) | 8.54[3] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | M2V[3] |
| Astrometry | |
| Radial velocity (Rv) | −17.30±0.09[4] km/s |
| Proper motion (μ) | RA: 0.259 mas/yr[2] Dec.: −773.096 mas/yr[2] |
| Parallax (π) | 142.0543±0.0160 mas[2] |
| Distance | 22.960 ± 0.003 ly (7.0396 ± 0.0008 pc) |
| Absolute magnitude (MV) | 8.46[1] |
| Details | |
| Mass | 0.54[5] M☉ |
| Radius | 0.54[6] R☉ |
| Luminosity | 0.05[6] L☉ |
| Surface gravity (log g) | 4.72[5] cgs |
| Temperature | 3,729[6] K |
| Metallicity [Fe/H] | −0.21[5] dex |
| Rotational velocity (v sin i) | 2.8[3] km/s |
| Age | 12.3[5] Gyr |
| Other designations | |
| BD+61°2068, GJ 809, HD 199305, HIP 103096[7] | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
This is a high proper motion star that moves about 0.77 arcseconds per year relative to background stars.[7] In physical terms it is travelling with a space velocity of 31.1 km/s relative to the Solar System.[8] The galactic orbit of this star carries it 21,300 ly from the Galactic Center at its perigee to 30,600 ly at its apogee. The orbital eccentricity is 17.8% with the semi-major axis of 25,956 ly and a semi-minor axis of 25,542 ly.[8]
Gliese 809 forms an optical double with the 9th magnitude star BD+61°2067, but this is an unrelated background star.[9]