22 Aquilae

22 Aquilae

Observation data Epoch J2000      Equinox J2000
Constellation	Aquila
Right ascension	19^h 16^m 31.03180^s[1]
Declination	+04° 50′ 05.2523″[1]
Apparent magnitude (V)	5.59[2]
Characteristics
Spectral type	A1 V[3] or A3 IV[4]
B−V color index	0.101±0.006[2]
Astrometry
Radial velocity (Rv)	−22.8±4.3[5] km/s
Proper motion (μ)	RA: +14.306[1] mas/yr Dec.: –11.083[1] mas/yr
Parallax (π)	4.7392 ± 0.0910 mas[1]
Distance	690 ± 10 ly (211 ± 4 pc)
Absolute magnitude (MV)	−0.48[2]
Details
Mass	2.89±0.11[6] M☉
Luminosity	161+27 −23[6] L☉
Temperature	8453±78[6] K
Rotational velocity (v sin i)	70[6] km/s
Other designations
22 Aql, AG+04 2489, BD+04° 4045, GC 26567, HD 180482, HIP 94727, HR 7303, SAO 143134, 2MASS J19163102+0450052[7]
Database references
SIMBAD	data

22 Aquilae, abbreviated 22 Aql, is a star in the equatorial constellation of Aquila. 22 Aquilae is its Flamsteed designation. It is a faint star but visible to the naked eye with an apparent visual magnitude of 5.59.^[2] The distance to 22 Aql can be estimated from its annual parallax shift of 4.74 mas,^[1] which yields a separation of 690 light years. It is moving closer to the Earth with a heliocentric radial velocity of −23 km/s.^[5]

Cowley et al. (1969) assigned this star a stellar classification of A3 IV,^[4] matching an evolving subgiant star that has exhausted the hydrogen at its core. Houk and Swift (1999) reassigned it as an A-type main-sequence star with a class of A1 V.^[3] It has nearly three times the mass of the Sun and is spinning with a projected rotational velocity of 70 km/s.^[6] The star is radiating 161^[6] times the Sun's luminosity from its photosphere at an effective temperature of 8,453 K.^[6]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
2. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
3. Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
4. Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
5. Gontcharov, G. A. (2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
6. Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
7. "22 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 31, 2018.