Omega2 Aquilae

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For other star systems with this Bayer designation, see Omega Aquilae.
Omega2 Aquilae
Diagram showing star positions and boundaries of the Aquila constellation and its surroundings
Cercle rouge 100%.svg

Location of ω2 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Aquila
Right ascension 19h 19m 53.06650s[1]
Declination +11° 32′ 05.8750″[1]
Apparent magnitude (V) 6.023[2]
Spectral type A2 V[3]
U−B color index +0.07[4]
B−V color index +0.08[4]
Radial velocity (Rv) −26[5] km/s
Proper motion (μ) RA: 43.77[1] mas/yr
Dec.: 22.57[1] mas/yr
Parallax (π) 12.27 ± 0.52[1] mas
Distance 270 ± 10 ly
(81 ± 3 pc)
Radius 2.0[6] R
Temperature 8,936[7] K
Rotational velocity (v sin i) 154[8] km/s
Other designations
29 Aquilae, 29 Aql, BD+11 3802, GC 26660, HD 181383, HIP 95002, HR 7332, PPM 136128, SAO 104728.[2]

Omega2 Aquilae (ω2 Aquilae, ω2 Aql) is the Bayer designation for a star in the equatorial constellation of Aquila, the eagle. It has an apparent visual magnitude of 6.0,[2] which is close to the lower limit of detectability with the naked eye. According to the Bortle Dark-Sky Scale, this star can be viewed from dark rural skies. As the Earth orbits about the Sun, this star undergoes a parallax shift of 12.27 mas.[1] This is equivalent to a physical distance of 270 light-years (83 parsecs) from Earth, give or take a 10 light year margin of error.

Analysis of the spectrum of this star shows it to match a stellar classification of A2 V,[3] indicating it is an A-type main sequence star. It is about double[6] the size of the Sun. The outer atmosphere is radiating energy at an effective temperature of 8,936 K,[7] giving it the white hue of an A-type star.[9] Omega2 Aquilae is spinning rapidly with a projected rotational velocity of 154 km/s.[8]


  1. ^ 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:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c "29 Aql -- Star", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-21. 
  3. ^ a b 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. 
  4. ^ a b Osawa, K.; Hata, S. (1962), "Three-color photometry of B8-A2 stars (II).", Annals of the Tokyo Astronomical Observatory, 7: 209, Bibcode:1962AnTok...7..209O. 
  5. ^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E. 
  6. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367: 521–524, arXiv:astro-ph/0012289Freely accessible, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451. 
  7. ^ a b Soubiran, C.; Le Campion, J.-F.; Cayrel de Strobel, G.; Caillo, A. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069Freely accessible, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247. 
  8. ^ a b Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785Freely accessible, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224. 
  9. ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, retrieved 2012-01-16. 

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