Gliese 65
Gliese 65, as seen during the Digitized Sky Survey | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cetus |
| Gliese 65 A (BL Ceti) | |
| Right ascension | 01h 39m 01.3773s |
| Declination | –17° 57′ 02.587″ |
| Apparent magnitude (V) | 12.8 |
| Gliese 65 B (UV Ceti) | |
| Right ascension | 01h 39m 01.6377s |
| Declination | –17° 57′ 01.001″ |
| Apparent magnitude (V) | 12.8 |
| Characteristics | |
| Gliese 65 A (BL Ceti) | |
| Spectral type | M5.5V |
| U−B color index | 1.10 |
| B−V color index | 1.87 |
| Variable type | UV Cet |
| Gliese 65 B (UV Ceti) | |
| Spectral type | M6 V |
| Variable type | UV Cet |
| Astrometry | |
| Parallax (π) | 371.92±0.42 mas |
| Distance | 8.770 ± 0.010 ly (2.689 ± 0.003 pc) |
| Gliese 65 A (BL Ceti) | |
| Proper motion (μ) | RA: 3385.316 mas/yr Dec.: 544.386 mas/yr |
| Absolute magnitude (MV) | 15.7 |
| Gliese 65 B (UV Ceti) | |
| Proper motion (μ) | RA: 3178.694 mas/yr Dec.: 584.061 mas/yr |
| Absolute magnitude (MV) | 15.7 |
| Orbit | |
| Period (P) | 26.38±0.002 yr |
| Semi-major axis (a) | 2.0584±0.0097" (5.459±0.002 AU) |
| Eccentricity (e) | 0.6172±0.0001 |
| Inclination (i) | 128.0±0.1° |
| Longitude of the node (Ω) | 325.9±0.1° |
| Periastron epoch (T) | 41333±8 MJD (17 January 1972) |
| Argument of periastron (ω) (secondary) | 103.2±0.1° |
| Details | |
| Gliese 65 A | |
| Mass | 0.122±0.002 M☉ |
| Radius | 0.165±0.006 R☉ |
| Luminosity | 0.00147±0.00005 L☉ |
| Surface gravity (log g) | 5.092±0.015 cgs |
| Temperature | 2784±58 K |
| Metallicity [Fe/H] | −0.03±0.20 dex |
| Rotation | 0.2430±0.0005 days |
| Rotational velocity (v sin i) | 28.2±2 km/s |
| Gliese 65 B | |
| Mass | 0.116±0.002 M☉ |
| Radius | 0.159±0.006 R☉ |
| Luminosity | 0.00125±0.00005 L☉ |
| Surface gravity (log g) | 5.113±0.015 cgs |
| Temperature | 2728±60 K |
| Metallicity [Fe/H] | −0.12±0.20 dex |
| Rotation | 0.2268±0.0003 days |
| Rotational velocity (v sin i) | 30.6±2 km/s |
| Other designations | |
| GJ 65, G 272-61, L 726-8, PLX 343.1 | |
| Gliese 65 A: BL Ceti, LHS 9, LP 768-27 | |
| Gliese 65 B: UV Ceti, LHS 10, LP 768-26 | |
| Database references | |
| SIMBAD | The system |
| A (BL Cet) | |
| B (UV Cet) | |
Gliese 65, also known as Luyten 726-8, is a binary star system that is one of Earth's nearest neighbors, at 8.8 light-years (2.7 parsecs) from Earth in the constellation Cetus. The two component stars are both flare stars with the variable star designations BL Ceti and UV Ceti.