Upsilon Aquilae

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Upsilon Aquilae
Diagram showing star positions and boundaries of the Aquila constellation and its surroundings
Cercle rouge 100%.svg

Location of υ Aquilae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 19h 45m 39.94763s[1]
Declination +07° 36′ 47.3717″[1]
Apparent magnitude (V) +5.889[2]
Spectral type A3 IV[3]
U−B color index +0.09[4]
B−V color index +0.18[4]
Radial velocity (Rv) –29.9[5] km/s
Proper motion (μ) RA: +54.10[1] mas/yr
Dec.: +0.50[1] mas/yr
Parallax (π) 18.65 ± 0.41[1] mas
Distance 175 ± 4 ly
(54 ± 1 pc)
Surface gravity (log g) 4.21[2] cgs
Temperature 7,906[2] K
Metallicity [Fe/H] –0.05[2] dex
Rotational velocity (v sin i) 42[6] km/s
Other designations
49 Aquilae, BD+07° 4210, HD 186689, HIP 97229, HR 7519, SAO 125032.[7]
Database references

Upsilon Aquilae (υ Aql, υ Aquilae) is the Bayer designation for a star in the equatorial constellation of Aquila. With an apparent visual magnitude of +5.91[4] it is a faint star but visible to the naked eye from suburban skies. It has an annual parallax shift of 18.65 milliarcsecond,[1] indicating a distance of around 175 light-years (54 parsecs).

Upsilon Aquilae is a subgiant star with a stellar classification of A3 IV.[3] The outer atmosphere is radiating energy into space at an effective temperature of 7,906 K,[2] which gives it the white-hot glow of an A-type star. It is spinning relatively quickly with a projected rotational velocity of 42 km/s.[6]


  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, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d e Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, Bibcode:2010A&A...515A.111S, arXiv:1004.1069Freely accessible, doi:10.1051/0004-6361/201014247. 
  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 c Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J. 
  5. ^ Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Washington, Carnegie Institution of Washington: 0, Bibcode:1953GCRV..C......0W. 
  6. ^ 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, Bibcode:2007A&A...463..671R, arXiv:astro-ph/0610785Freely accessible, doi:10.1051/0004-6361:20065224. 
  7. ^ "ups Aql -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-21. 

External links[edit]