70 Aquilae
Star in the constellation Aquila
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70 Aquilae, abbreviated 70 Aql, is a single[13] orange-hued star in the equatorial constellation of Aquila. 70 Aquilae is its Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.90.[2] The distance to 70 Aquilae, as determined from its annual parallax shift of 4.1 mas,[1] is around 800 light years. The star is moving closer to the Earth with a heliocentric radial velocity of −9 km/s.[7]
 | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Aquila |
| Right ascension | 20h 36m 43.63319s[1] |
| Declination | −02° 32′ 59.8367″[1] |
| Apparent magnitude (V) | 4.903[2] |
| Characteristics | |
| Evolutionary stage | red giant branch[1] |
| Spectral type | K4+ III Ba1,[3] K3 III,[4] or K5 II[5] |
| B−V color index | 1.606±0.041[6] |
| Astrometry | |
| Radial velocity (Rv) | −9.4±0.4[7] km/s |
| Proper motion (μ) | RA: +10.862[1] mas/yr Dec.: –15.416[1] mas/yr |
| Parallax (π) | 4.0825±0.1052 mas[1] |
| Distance | 800 ± 20 ly (245 ± 6 pc) |
| Absolute magnitude (MV) | −3.05[6] |
| Details | |
| Mass | 6.2±0.6[8] M☉ |
| Radius | 96[9] R☉ |
| Luminosity (bolometric) | 4,072[2] L☉ |
| Surface gravity (log g) | 1.9[10] cgs |
| Temperature | 3,900[2] K |
| Metallicity [Fe/H] | −0.294±0.093[11] dex |
| Rotational velocity (v sin i) | 1.9[10] km/s |
| Age | 63.1±17.8[8] Myr |
| Other designations | |
| 70 Aql, BD−03°4961, FK5 3648, HD 196321, HIP 101692, HR 7873, SAO 144624[12] | |
| Database references | |
| SIMBAD | data |
Classification
Perkins et al. (1989) found a stellar classification of K4+ III Ba1[3] for this star, suggesting it is a K-type giant with abundance anomaly of barium.[14] Houk and Swift (1999) matched an ordinary giant with a class of K3 III.[4] Many sources[2][8][13][10][14] still use the 1991 Bright Star Catalogue classification of K5 II,[5] which instead suggests a bright giant star.
Size and temperature
The interferometry-measured angular diameter of this star, after correcting for limb darkening, is 3.27±0.04 mas,[15] which, at its estimated distance, equates to a physical radius of roughly 96 times the radius of the Sun.[9] 70 Aquilae is about 63 million years old with 6 times the mass of the Sun.[8] It is radiating 4,072 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,900 K.[2]