6 Boötis
Star in the constellation Boötes
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6 Boötis is a binary star[4] system in the northern constellation of Boötes,[10] located around 460 light years away from the Sun.[1] It has the Bayer designation e Boötis; 6 Boötis is the Flamsteed designation.[10] The system is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.92.[2] It is moving closer to the Earth with a heliocentric radial velocity of −3 km/s.[2]
  | |
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| Constellation | Boötes |
| Right ascension | 13h 49m 42.82223s[1] |
| Declination | +21° 15′ 50.8580″[1] |
| Apparent magnitude (V) | 4.92[2] |
| Characteristics | |
| Spectral type | K4 III[3] + M8 V[4] |
| B−V color index | 1.432±0.013[2] |
| Astrometry | |
| Radial velocity (Rv) | −3.71±0.48[1] km/s |
| Proper motion (μ) | RA: +33.773[1] mas/yr Dec.: +10.842[1] mas/yr |
| Parallax (π) | 7.1527±0.3659 mas[1] |
| Distance | 460 ± 20 ly (140 ± 7 pc) |
| Absolute magnitude (MV) | −0.49[2] |
| Orbit[4] | |
| Period (P) | 944±8 d |
| Eccentricity (e) | 0.41±0.09 |
| Periastron epoch (T) | 2,444,739.5±31.0 JD |
| Argument of periastron (ω) (secondary) | 359±15° |
| Semi-amplitude (K1) (primary) | 1.19±0.15 km/s |
| Details | |
| Mass | 5.0[5] M☉ |
| Radius | 36[6] R☉ |
| Luminosity | 382[6] L☉ |
| Surface gravity (log g) | 1.49[7] cgs |
| Temperature | 4,185[7] K |
| Metallicity [Fe/H] | −0.24[8] dex |
| Rotational velocity (v sin i) | 2.0[9] km/s |
| Age | 1.9[7] Gyr |
| Other designations | |
| e Boötis, 6 Boo, BD+21°2578, FK5 3098, GC 18683, HD 120539, HIP 67480, HR 5201, SAO 83015[10] | |
| Database references | |
| SIMBAD | data |
This is a single-lined spectroscopic binary system with an orbital period of 2.58 years and an eccentricity of 0.4.[4] The visible component is an evolved giant star with a stellar classification of K4 III.[3] Its measured angular diameter is 2.53±0.12 mas.[11] At the estimated distance of the star, this yields a physical size of about 36 times the radius of the Sun.[6] The star is radiating 382 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,185 K.[7] Its companion is probably a low mass red dwarf of around class M8 V.[4]