Alpha Lacertae
Alpha Lacertae, Latinised from α Lacertae, is a single white-hued star in the constellation of Lacerta, located 103 light-years from the Sun. It is the brightest star in Lacerta with an apparent visual magnitude of 3.76. The star is moving closer to the Earth with a heliocentric radial velocity of −4.5 km/s.
α Lacertae in optical light | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lacerta |
| Right ascension | 22h 31m 17.50131s |
| Declination | +50° 16′ 56.9682″ |
| Apparent magnitude (V) | 3.76 |
| Characteristics | |
| Spectral type | A1 V |
| U−B color index | 0.00 |
| B−V color index | 0.031±0.003 |
| R−I color index | −0.03 |
| Astrometry | |
| Radial velocity (Rv) | −4.5±0.9 km/s |
| Proper motion (μ) | RA: 137.51 mas/yr Dec.: 17.01 mas/yr |
| Parallax (π) | 31.79 ± 0.12 mas |
| Distance | 102.6 ± 0.4 ly (31.5 ± 0.1 pc) |
| Absolute magnitude (MV) | 1.27 |
| Details | |
| Mass | 2.194 M☉ |
| Radius | 2.1432±0.0737 R☉ |
| Luminosity | 27.6750±0.2138 L☉ |
| Surface gravity (log g) | 4.27±0.14 cgs |
| Temperature | 9,050±157 K |
| Rotational velocity (v sin i) | 128 km/s |
| Age | 400 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an ordinary A-type main-sequence star with a stellar classification of A1 V, which indicates it is generating energy through hydrogen fusion at its core. It is around 400 million years old with a relatively high rate of spin, showing a projected rotational velocity of 128 km/s. The star has 2.2 times the mass of the Sun and 2.1 times the Sun's radius. It is radiating 28 times the Sun's luminosity from its photosphere at an effective temperature of 9,050 K.
Alpha Lacertae has a visual companion, CCDM J22313+5017B, of spectral type A and apparent visual magnitude 11.8, approximately 36 arcseconds away. The companion is optical, a chance line-of-sight coincidence.