HD 179886

HD 179886
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Telescopium
Right ascension 19h 16m 21.7422s[1]
Declination −45° 27′ 57.704″[1]
Apparent magnitude (V) 5.371[2] (5.59 + 8.63)[3]
Characteristics
Evolutionary stage red giant branch[1]
Spectral type K3 III[4]
B−V color index +1.35[5]
Astrometry
Radial velocity (Rv)6.3±0.8[6] km/s
Proper motion (μ) RA: −3.013[1] mas/yr
Dec.: +10.017[1] mas/yr
Parallax (π)4.6441 ± 0.1537 mas[1]
Distance700 ± 20 ly
(215 ± 7 pc)
Absolute magnitude (MV)−0.7[7]
Details
Mass1.11[8] M☉
Radius36.75[9] R☉
Luminosity365[10] L☉
Surface gravity (log g)1.3[8] cgs
Temperature4,622[10] K
Metallicity [Fe/H]+0.15[8] dex
Rotational velocity (v sin i)2.4±1.1[11] km/s
Other designations
51 G. Telescopii, CD−45°13072, CPD−45°9660, GC 26526, HD 179886, HIP 94712, HR 7289, SAO 229584, WDS J19164-4528AB
Database references
SIMBADdata

HD 179886 (HR 7289) is a binary star[3] located in the southern constellation Telescopium. It has a combined apparent magnitude of 5.37,[2] making it faintly visible to the naked eye if viewed under ideal conditions. The system is situated at a distance of 700 light years[1] but is receding with a heliocentric radial velocity of 6.3 km/s.[6]

As of 2018, the two stars have a separation of 0.4 arcseconds along a position angle of 205°[12]

The brighter component has a stellar classification of K3 III, indicating that the object is an ageing K-type giant. Models show it to be on the red giant branch,[1] a stage of stellar evolution where the star is fusing hydrogen in a shell around an inert core of helium. It has an angular diameter of 1.95±0.03,[13] yielding a diameter 37 times that of the Sun[9] at its estimated distance. At present it has 111% the mass of the Sun[8] and radiates at 365 L☉[10] from its enlarged photosphere at an effective temperature of 4,622 K,[10] giving it an orange glow. HD 179886A has a metallicity 141% that of the Sun[8] and spins modestly with a projected rotational velocity of 2.4 km/s.[11]

  1. ^ a b c d e f g h Cite error: The named reference DR3 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 Eggleton2008 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Houk1978 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Corben1971 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 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 c d e Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference dr2 was invoked but never defined (see the help page).
  10. ^ a b c d Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference DeMederios2014 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Mason2001 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Richichi2005 was invoked but never defined (see the help page).