HD 191984

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
HD 191984
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension  20h 12m 35.12436s[1]
Declination +00° 52′ 01.3864″[1]
Apparent magnitude (V) 6.246[2]
Spectral type B9p CR(EU SR)[3] + A0[4]
U−B color index −0.033[2]
B−V color index +0.090[2]
Radial velocity (Rv)−19[5] km/s
Proper motion (μ) RA: +2.12[1] mas/yr
Dec.: −20.85[1] mas/yr
Parallax (π)5.54 ± 1.10 mas
Distanceapprox. 600 ly
(approx. 180 pc)
Luminosity82[6] L
Temperature8,477[6] K
Rotational velocity (v sin i)150[7] km/s
Other designations
BD+00° 4444, HD 191984, HIP 99585, HR 7717.
Database references
Database references

HD 191984 is a double star in the equatorial constellation of Aquila. As of 2011, the components have an angular separation of 2.52 along a position angle of 205.7°.[8]


  1. ^ a b c d van Leeuwen, F. (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
  2. ^ a b c Rakos, K. D.; et al. (February 1982), "Photometric and astrometric observations of close visual binaries", Astronomy and Astrophysics Supplement Series, 47: 221–235, Bibcode:1982A&AS...47..221R
  3. ^ 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. ^ Renson, P.; Manfroid, J. (May 2009), "Catalogue of Ap, HgMn and Am stars" (PDF), Astronomy and Astrophysics, 498 (3): 961–966, Bibcode:2009A&A...498..961R, doi:10.1051/0004-6361/200810788
  5. ^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Washington, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W
  6. ^ a b McDonald, I.; Zijlstra, A. A; Boyer, M. L. (2012). "Fundamental Parameters and Infrared Excesses of Hipparcos Stars". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–57. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x.
  7. ^ Abt, Helmut A.; Morrell, Nidia I. (July 1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182
  8. ^ Mason, Brian D.; et al. (May 2012), "Speckle Interferometry at the U.S. Naval Observatory. XVIII", The Astronomical Journal, 143 (5): 6, Bibcode:2012AJ....143..124M, doi:10.1088/0004-6256/143/5/124, 124

External links[edit]