Beta Aquilae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 55m 18.793s |
| Declination | +06° 24′ 24.35″ |
| Apparent magnitude (V) | 3.87 + 12.0 |
| Characteristics | |
| Spectral type | G9.5 IV + M2.5 V |
| U−B color index | 0.48 |
| B−V color index | 0.86 |
| R−I color index | 0.49 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | −40.3±0.09 km/s |
| Proper motion (μ) | RA: +45.944 mas/yr Dec.: −480.965 mas/yr |
| Parallax (π) | 73.5249±0.1415 mas |
| Distance | 44.36 ± 0.09 ly (13.60 ± 0.03 pc) |
| Absolute magnitude (MV) | +3.03 |
| Details | |
| A | |
| Mass | 1.24±0.02 M☉ |
| Radius | 3.096±0.015 R☉ |
| Luminosity | 5.878±0.032 L☉ |
| Surface gravity (log g) | 3.549±0.002 cgs |
| Temperature | 5,090±15 K |
| Metallicity [Fe/H] | −0.20±0.04 dex |
| Rotation | 5.08697±0.00031 days |
| Rotational velocity (v sin i) | 22.28 km/s |
| Age | 4.77±0.50 Gyr |
| Other designations | |
| Alshain, Alschairn, β Aql, 60 Aquilae, BD+06°4357, FK5 749, GC 27587, GJ 771, HD 188512, HIP 98036, HR 7602, SAO 125235, PPM 168947, WDS 19553+0624, LHS 5350a, LTT 15822 | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
Beta Aquilae is a triple star system in the equatorial constellation of Aquila. Its name is a Bayer designation that is Latinized from β Aquilae, and abbreviated Beta Aql or β Aql. This system is visible to the naked eye as a point-like source with an apparent visual magnitude of 3.87. Based on parallax measurements, it is located at a distance of 44.4 light-years. It is drifting closer to the Sun with a radial velocity of −40 km/s, and is predicted to approach to within 27 light-years (8.4 pc) in roughly 207,000 years.
Its two visible components are designated Beta Aquilae A and B. The former is formally named Alshain /ælˈʃeɪn/, the traditional name for the system.