HD 179791

HD 179791
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 19h 13m 44.03146s[1]
Declination +05° 30′ 56.1725″[1]
Apparent magnitude (V) 6.48[2]
Characteristics
Evolutionary stage main sequence[3]
Spectral type A3 V[4]
U−B color index +0.10[2]
B−V color index +0.09[2]
Variable type suspected[5]
Astrometry
Radial velocity (Rv)+16.2[6] km/s
Proper motion (μ) RA: +6.819[1] mas/yr
Dec.: −9.809[1] mas/yr
Parallax (π)5.2966 ± 0.0569 mas[1]
Distance616 ± 7 ly
(189 ± 2 pc)
Absolute magnitude (MV)0.66[7]
Details
Mass2.55±0.15[3] M☉
Radius2.5[8] R☉
Luminosity65.8+21.0
−16.0[3] L☉
Temperature8912+166
−162[3] K
Rotational velocity (v sin i)196[3] km/s
Other designations
NSV 11827, BD+05° 4081, HD 179791, HIP 94478, HR 7288, SAO 124410[9]
Database references
SIMBADdata

HD 179791 is suspected variable star[5] in the equatorial constellation of Aquila. It is a challenge to see with the naked eye even under good viewing conditions, having an apparent visual magnitude of 6.48.[2] The distance to HD 179791 can be estimated from its annual parallax shift of 5.3 mas,[1] which yields a value of 616 light years. It is moving further from the Earth with a heliocentric radial velocity of +16 km/s.[6] Astrometric measurements of the star show changes in motion that may indicate it is a member of a close binary system.[10]

This is an A-type main-sequence star with a stellar classification of A3 V.[4] It is a suspected chemically peculiar star and formerly a candidate Lambda Boötis star.[11] The status as a Lambda Boötis star was reviewed and changed to non-member in 2015.[12] It is spinning rapidly with a projected rotational velocity of 196 km/s.[3] The star has 2.55[3] times the mass of the Sun and about 2.5[8] times the Sun's radius. It is radiating 66[3] times the Sun's luminosity from its photosphere at an effective temperature of 8,912 K.[3]

  1. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference mnassa24_120 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h i Cite error: The named reference zorec2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference aj74_375 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference CADARS was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference mason1999 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Renson2009 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Cheng2017 was invoked but never defined (see the help page).