  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 36m 53.44952s [1] |
| Declination | –7° 01′ 38.9176″ [1] |
| Apparent magnitude (V) | +4.957 [2] |
| Characteristics | |
| Spectral type | B0.5 III [3] |
| U−B color index | –0.861 [2] |
| B−V color index | –0.028 [2] |
| Astrometry | |
| Radial velocity (Rv) | –19.4 [4] km/s |
| Proper motion (μ) |
RA: +1.63
[1]
mas/
yr Dec.: –2.65 [1] mas/ yr |
| Parallax (π) | 1.94 ± 0.20 mas [1] |
| Distance | approx. 1,700
ly (approx. 520 pc) |
| Absolute magnitude (MV) | −3.60 [5] |
| Details | |
| Mass | 15.50 ± 0.61 [6] M☉ |
| Radius | 12.5 [7] R☉ |
| Luminosity | 52,630 [6] L☉ |
| Surface gravity (log g) | 3.5 [8] cgs |
| Temperature | 26,500 [6] K |
| Metallicity [Fe/H] | −0.16 [5] dex |
| Rotational velocity (v sin i) | 265 [9] km/s |
| Age | 11.1 ± 0.5 [3] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Kappa Aquilae, Latinized from κ Aquilae, is the Bayer designation for a star in the equatorial constellation of Aquila. It is a faint star at apparent visual magnitude +4.957, [2] but bright enough to be seen with the naked eye in dark suburban skies. The annual parallax is only 1.94 mas, [1] which equates to a distance of approximately 1,700 light-years (520 parsecs) from Earth (with a 10% margin of error).
The spectrum of Kappa Aquilae matches a stellar classification of B0.5 III, [3] where the luminosity class of III is typically associated with evolved giant stars. This is a star with 15.50 [6] times the Sun's mass and 12.5 [7] times the radius of the Sun. Massive stars like this blaze brightly; it is radiating 52,630-fold [6] the Sun's luminosity from its outer atmosphere with an effective temperature of 26,500 K, [6] giving it the intense blue-white glow of a B-type star. It is only 11 million years of age [3] and is spinning rapidly with a projected rotational velocity of 265 km/s. [9]
Etymology
In Chinese, 右旗 (Yòu Qí), meaning Right Flag, refers to an asterism consisting of κ Aquilae, μ Aquilae, σ Aquilae, δ Aquilae, ν Aquilae, 42 Aquilae, ι Aquilae, HD 184701 and 56 Aquilae. [11] Consequently, the Chinese name for κ Aquilae itself is 右旗八 (Yòu Qí bā, English: the Eighth Star of Right Flag.) [12]
This star, together with η Aql, θ Aql, δ Aql, ι Aql and λ Aql were once part of the now-obsolete constellation Antinous. [13]
References
- ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv: 0708.1752, Bibcode: 2007A&A...474..653V, doi: 10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode: 1966PDAUC...1....1G.
- ^ a b c d Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv: 1007.4883, Bibcode: 2011MNRAS.410..190T, doi: 10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ^ Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg, 35 (35), Astronomisches Rechen-Institut Heidelberg: 1, Bibcode: 1999VeARI..35....1W.
- ^ a b 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.
- ^ a b c d e f Hohle, M. M.; Neuhäuser, R.; Schutz, B. F. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv: 1003.2335, Bibcode: 2010AN....331..349H, doi: 10.1002/asna.200911355, S2CID 111387483.
- ^ a b Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society, 189 (3): 601–605, Bibcode: 1979MNRAS.189..601U, doi: 10.1093/mnras/189.3.601.
- ^ Frémat, Y.; et al. (September 2005), "Effects of gravitational darkening on the determination of fundamental parameters in fast-rotating B-type stars", Astronomy and Astrophysics, 440 (1): 305–320, arXiv: astro-ph/0503381, Bibcode: 2005A&A...440..305F, doi: 10.1051/0004-6361:20042229, S2CID 19016751.
- ^ a b Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode: 2002ApJ...573..359A, doi: 10.1086/340590.
- ^ "* kap Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-01-13.
- ^ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 3 日
- ^ Ian Ridpath's Star Tales - Antinous
