6 Lacertae
Star in the constellation Lacerta
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6 Lacertae is a binary star[5] system in the northern constellation of Lacerta, located around 1,900 light years from the Sun.[1] It is visible to the naked eye as a dim, blue-white hued star with a combined apparent visual magnitude of 4.52.[2] The system is moving closer to the Earth with a heliocentric radial velocity of −9 km/s,[2] and is a suspected member of the Lac OB1 association.[4]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Lacerta |
| Right ascension | 22h 30m 29.26005s[1] |
| Declination | +43° 07′ 24.1565″[1] |
| Apparent magnitude (V) | 4.52[2] |
| Characteristics | |
| Spectral type | B2 IV[3] |
| B−V color index | −0.086±0.018[2] |
| Astrometry | |
| Radial velocity (Rv) | −8.7±0.9[2] km/s |
| Proper motion (μ) | RA: −4.800[1] mas/yr Dec.: −2.598[1] mas/yr |
| Parallax (π) | 1.7577±0.2697 mas[1] |
| Distance | approx. 1,900 ly (approx. 570 pc) |
| Absolute magnitude (MV) | −2.62[4] |
| Orbit[5] | |
| Period (P) | 880 days |
| Eccentricity (e) | 0.30 |
| Periastron epoch (T) | 2,416,300 JD |
| Argument of periastron (ω) (secondary) | 190° |
| Semi-amplitude (K1) (primary) | 9 km/s |
| Details | |
| Mass | 12.5±0.6[6] M☉ |
| Radius | 6.9[7] R☉ |
| Luminosity (bolometric) | 34,590[8] L☉ |
| Surface gravity (log g) | 3.56[9] cgs |
| Temperature | 21,150[8] K |
| Metallicity [Fe/H] | −0.04[9] dex |
| Rotational velocity (v sin i) | 70[10] km/s |
| Age | 15.7±0.1[6] Myr |
| Other designations | |
| 6 Lac, BD+42°4420, FK5 3800, HD 213420, HIP 111104, HR 8579, SAO 52079[11] | |
| Database references | |
| SIMBAD | data |
This system forms a single-lined spectroscopic binary with an orbital period of 880 days and an eccentricity of 0.3.[5] The visible component has a stellar classification of B2 IV,[3] matching a B-type subgiant star. It is about 16 million years old[6] with a relatively high projected rotational velocity of 70 km/s.[10] The star has 12.5 times the mass of the Sun[6] and about 7 times the Sun's radius.[7] It is radiating a net 34,590 times the Sun's luminosity[8] from its photosphere at an effective temperature of 21,150 K.[8]