HD 161988

HD 161988
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Apus
Right ascension 17h 57m 41.686s[1]
Declination −76° 10′ 40.62″[1]
Apparent magnitude (V) 6.07±0.01[2]
Characteristics
Evolutionary stage red giant branch[3]
Spectral type K2 III[4]
U−B color index +1.28[5]
B−V color index +1.20[5]
Astrometry
Radial velocity (Rv)+36.8±0.4[6] km/s
Proper motion (μ) RA: +2.464 mas/yr[1]
Dec.: −1.867 mas/yr[1]
Parallax (π)5.2546 ± 0.022 mas[1]
Distance621 ± 3 ly
(190.3 ± 0.8 pc)
Absolute magnitude (MV)−0.26[7]
Details
Mass3.05[8] M☉
Radius20.8[9] R☉
Luminosity185[10] L☉
Surface gravity (log g)2.04±0.02[3] cgs
Temperature4,498[10] K
Metallicity [Fe/H]−0.13[11] dex
Rotational velocity (v sin i)2.1±1.3[12] km/s
Other designations
63 G. Apodis[13], CD−76°919, CPD−76 1226, HD 161988, HIP 87926, HR 6635, SAO 257542, WDS J17577-7611A[14]
Database references
SIMBADdata

HD 161988, also known as HR 6635, is a solitary, orange hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.07,[2] allowing it to be faintly visible to the naked eye. Parallax measurements place it at a distance of 621 light years,[1] and it is currently receding with a heliocentric radial velocity of 36.8 km/s.[6]

The object has a stellar classification of K2 III,[4] indicating that it is a red giant. Gaia Data Release 3 models place it on the red giant branch. At present it has 3.05 times the mass of the Sun[8] and an enlarged radius of 20.8 R☉.[9] It shines at 185 times the luminosity of the Sun from its photosphere at an effective temperature of 4,498 K.[10] HD 161988 has an iron abundance 74% that of the Sun,[11] making it slightly metal deficient. Like most giants, it spins modestly with a projected rotational velocity of 2.1 km/s.[12]

HD 161988 has a 14th magnitude optical companion located 26.4 arcseconds away along a position angle of 122°.[15]

  1. ^ a b c d e Cite error: The named reference edr3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference clpl4_99 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 Kervella2021 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference demedeiros2014 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Mason2001 was invoked but never defined (see the help page).