Lambda Aquilae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 06m 14.939s |
| Declination | −04° 52′ 57.23″ |
| Apparent magnitude (V) | 3.43 |
| Characteristics | |
| λ Aql A | |
| Evolutionary stage | Main sequence |
| Spectral type | B9Vn |
| U−B color index | −0.27 |
| B−V color index | −0.048 |
| Variable type | Constant |
| λ Aql B | |
| Evolutionary stage | Main sequence |
| Astrometry | |
| Radial velocity (Rv) | −8.8±0.9 km/s |
| Proper motion (μ) | RA: −19.120 mas/yr Dec.: −89.427 mas/yr |
| Parallax (π) | 25.6409±0.4211 mas |
| Distance | 127 ± 2 ly (39.0 ± 0.6 pc) |
| Absolute magnitude (MV) | +0.54 |
| Orbit | |
| Period (P) | 15 days |
| Semi-major axis (a) | 0.18 au |
| Details | |
| λ Aql A | |
| Mass | 3.1±0.1 M☉ |
| Radius | 2.27±0.13 R☉ |
| Luminosity | 55 L☉ |
| Surface gravity (log g) | 4.15±0.05 cgs |
| Temperature | 12,100±100 K |
| Metallicity [Fe/H] | 0.00 dex |
| Rotational velocity (v sin i) | 103 km/s |
| Age | 90 Myr |
| λ Aql B | |
| Mass | 0.62 M☉ |
| Radius | 0.60 R☉ |
| Temperature | 4,250 K |
| Other designations | |
| λ Aql, 16 Aql, BD−05°4876, FK5 717, GC 26285, HD 177756, HIP 93805, HR 7236, SAO 143021, PPM 202530 | |
| Database references | |
| SIMBAD | data |
Lambda Aquilae is a binary star in the constellation Aquila. Its identifier is a Bayer designation that is Latinized from λ Aquilae, and abbreviated Lambda Aql or λ Aql. This star has the traditional name Al Thalimain, pronounced /ælˌθælɪˈmeɪn/, which it shares with ι Aquilae. The name is derived from the Arabic الظلیمين al-ẓalīmayn "the two ostriches". Lambda Aquilae might be more precisely called Al Thalimain Prior. It has an apparent visual magnitude of 3.43, which is bright enough to be seen with the naked eye. Parallax measurements place it at a distance of about 127 light-years (39 parsecs) from Earth. It is drifting closer to the Sun with a radial velocity of −9 km/s.