HD 156846

HD 156846
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension 17h 20m 34.31093s[1]
Declination −19° 20′ 01.4944″[1]
Apparent magnitude (V) 6.506[2] + 14.10[3]
Characteristics
Spectral type G1V[4] + M4V[5]
B−V color index 0.557[2]
Astrometry
Radial velocity (Rv)−68.50±0.22[6] km/s
Proper motion (μ) RA: −137.102±0.097[1] mas/yr
Dec.: −143.204±0.074[1] mas/yr
Parallax (π)20.9210 ± 0.0508 mas[1]
Distance155.9 ± 0.4 ly
(47.8 ± 0.1 pc)
Absolute magnitude (MV)3.055[2]
Details[2]
A
Mass1.35±0.045 M☉
Radius2.12±0.12 R☉
Luminosity5.07[6] L☉
Surface gravity (log g)3.92±0.08 cgs
Temperature5,969±44 K
Metallicity [Fe/H]+0.17±0.04 dex
Rotational velocity (v sin i)5.05±0.50 km/s
Age2.8+0.1
−0.2[6] Gyr
B
Mass0.59[5] M☉
Other designations
BD−19°4605, GC 23420, HD 156846, HIP 84856, HR 6441, SAO 160474[7]
Database references
SIMBADdata

HD 156846 is a binary star[5] system in the equatorial constellation of Ophiuchus, positioned a degree SSE of Messier 9.[8] It has a yellow hue and is just barely bright enough to be visible to the naked eye with an apparent visual magnitude of 6.5.[2] The system is located at a distance of 156 light years from the Sun based on parallax.[1] It is drifting closer with a radial velocity of −68.5 km/s, and is predicted to come to within 85.0 light-years in about 476,000 years.[6]

The primary, component A, is a G-type star with a stellar classification of G1V.[4] The absolute visual magnitude of this star is 1.13 magnitudes above the main sequence, indicating it has evolved slightly off the main sequence.[2] It has 1.35 times the mass of the Sun and 2.12 times the Sun's radius.[2] The star is an estimated 2.8[6] billion years old and is spinning with a projected rotational velocity of 5 km/s.[2] It is radiating five[6] times the luminosity of the Sun from its photosphere at an effective temperature of 5,969 K.[2]

The magnitude 14.4 secondary companion, component B, was discovered by the American astronomer R. G. Aitken in 1910.[3] It lies at an angular separation of 5.1″ from the primary, corresponding to a projected separation of 250 AU. This is a red dwarf with a class of M4V and has an estimated 59% of the Sun's mass.[5]

  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 e f g h i Cite error: The named reference Kane2011 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1988 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Fontanive2019 was invoked but never defined (see the help page).
  6. ^ a b c d e f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Sinnott1997 was invoked but never defined (see the help page).