Gliese 806
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 20h 45m 04.09925s[2] |
| Declination | +44° 29′ 56.6451″[2] |
| Apparent magnitude (V) | +10.79[1] |
| Characteristics | |
| Spectral type | dM1.5[3] |
| B−V color index | 1.491±0.005[1] |
| Astrometry | |
| Radial velocity (Rv) | −24.99±0.15[2] km/s |
| Proper motion (μ) | RA: 434.028 mas/yr[2] Dec.: 271.022 mas/yr[2] |
| Parallax (π) | 82.8903±0.0167 mas[2] |
| Distance | 39.348 ± 0.008 ly (12.064 ± 0.002 pc) |
| Absolute magnitude (MV) | +10.31[1] |
| Details | |
| Mass | 0.423±0.010[3] M☉ |
| Radius | 0.4144±0.0038[4] R☉ |
| Luminosity | 0.0026±0.0003[3] L☉ |
| Surface gravity (log g) | 4.89±0.07[3] cgs |
| Temperature | 3,586±51[3] K |
| Metallicity [Fe/H] | −0.28±0.07[4] dex |
| Rotation | 34.6–48.1 d[4] |
| Rotational velocity (v sin i) | 0.46[5] km/s |
| Age | ~3[6] Gyr |
| Other designations | |
| NSV 13280, BD+44 3567, GJ 806, HIP 102401, LTT 16068, TOI-4481, TIC 239332587, TYC 3178-00633-1, 2MASS J20450403+4429562[7][8] | |
| Database references | |
| SIMBAD | data |
Gliese 806 is a star in the northern constellation of Cygnus, located about a degree to the southeast of the bright star Deneb.[9] It is invisible to the naked eye with an apparent visual magnitude of +10.79.[1] The star is located at a distance of 39.3 light years from the Sun based on stellar parallax.[2] It is drifting closer with a radial velocity of −24.6 km/s, and is predicted to come to within 30.1 light-years in ~198,600 years.[10] The star hosts two known planetary companions.[4]
The stellar classification of Gliese 806 is dM1.5,[3] which indicates this is a small red dwarf star – an M-type main-sequence star that is generating energy through core hydrogen fusion. It is roughly three billion years old[6] and is spinning with a projected rotational velocity of 0.46 km/s.[5] The star has 42% of the mass and radius of the Sun. It is radiating 0.3% of the luminosity of the Sun from its photosphere at an effective temperature of 3,586 K.[3]
Planetary system
[edit | edit source]In 1989, Marcy and Benitz detected a periodicity of 416 days in radial velocity variation, inferring the possible presence of a companion with a mass of about 0.011 M☉.[11] However, this candidate object was never confirmed.
More recently, observations by TESS have found a candidate transiting planet with a period of less than a day.[8] In January 2023, this planet was confirmed and a second, non-transiting planet found via radial velocity observations. A third radial velocity signal was also found, but the study was unable to confirm it as having a planetary origin. All known planets are super-Earths, and the inner transiting planet Gliese 806 b is likely to be rocky.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.90±0.17 M🜨 | 0.01406±0.00030 | 0.9263237±0.0000009 | — | 87.7+0.6 −0.5° |
1.331±0.023 R🜨 |
| c | ≥5.80±0.30 M🜨 | 0.0523±0.0011 | 6.64064±0.00025 | — | — | — |
| (unconfirmed) | ≥8.50±0.45 M🜨 | 0.0844±0.0017 | 13.60588±0.00065 | — | — | — |
See also
[edit | edit source]References
[edit | edit source]- ^ a b c d e Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). XHIP record for this object at VizieR.
- ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Gaia DR3 record for this source at VizieR.
- ^ a b c d e f g Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).