Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Ophiuchus |
Right ascension | 17h 30m 23.79699s [1] |
Declination | −01° 03′ 46.4882″ [1] |
Apparent magnitude (V) | +5.31 [2] (6.02 + 5.93) [3] |
Characteristics | |
Evolutionary stage | Subgiant [4] |
Spectral type | G9IV-V + G9IV-V [3] |
B−V color index | +0.715±0.013 [5] |
Astrometry | |
Radial velocity (Rv) | −76.98±0.05 [5] km/s |
Proper motion (μ) |
RA: −127.77
[1]
mas/
yr Dec.: −168.61 [1] mas/ yr |
Parallax (π) | 61.19 ± 0.68 mas [1] |
Distance | 53.3 ± 0.6
ly (16.3 ± 0.2 pc) |
Absolute magnitude (MV) | 4.24 [5] |
Orbit [3] | |
Period (P) | 46.34±0.021 yr |
Semi-major axis (a) | 977.±3.3 mas |
Eccentricity (e) | 0.168±0.0025 |
Inclination (i) | 99.1±0.11° |
Longitude of the node (Ω) | 332.3±0.13° |
Periastron epoch (T) | 1870.0±0.16 Byr |
Argument of periastron (ω) (secondary) | 148.±1.3° |
Details | |
A | |
Mass | 0.963±0.005 [6] M☉ |
Radius | 1.7 [2] R☉ |
Luminosity | 2.5 [2] L☉ |
Surface gravity (log g) | 4.00 [2] cgs |
Temperature | 5,500±150 [2] K |
Age | 12.3 [7] Gyr |
B | |
Mass | 0.951±0.005 [6] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
HD 158614 is a visual binary star system in the equatorial constellation of Ophiuchus. The system is visible to the naked eye with a combined apparent visual magnitude of +5.31. [2] It is located at a distance of 53.3 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −77 km/s [5] and is predicted to come to within 11.0 light-years in around 196,000 years. [9] The system has been included as a candidate member of the Zeta Herculis moving group. [10] However, chemical abundances appear to rule that out. [11]
The pair were found to be a double star by F. G. W. Struve in 1827 and given the catalogue identifier Σ 2173 (now STF 2173). Since then it has completed multiple orbits, [12] yielding orbital elements showing a period of 46.3 years and an eccentricity of 0.17. [3] The two components have similar spectra that match a stellar classification of G9IV-V. [3] They show almost no luminosity variation; one of the pair appears to vary by 0.002 in magnitude. [4] Both components have a slightly lower mass than the Sun: 96% and 95%, respectively. [6] The system is estimated to be 12.3 billion years old. [7]
This binary was included in a search for brown dwarfs that turned up no large companions.[ citation needed]