| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 19h 40m 05.79185s[1] |
| Declination | +18° 00′ 50.0046″[1] |
| Apparent magnitude (V) | 6.13[2] |
| Characteristics | |
| Spectral type | G0V[3] or F4III[4] |
| B−Vcolor index | 0.434±0.004[2] |
| Astrometry | |
| Radial velocity (Rv) | +1.667±0.0024[1] km/s |
| Proper motion (μ) | RA: +14.630[1]mas/yr Dec.: −20.160[1]mas/yr |
| Parallax (π) | 8.5307±0.1848 mas[1] |
| Distance | 382 ± 8 ly (117 ± 3 pc) |
| Absolute magnitude (MV) | 0.82 |
| Orbit[5] | |
| Primary | A |
| Companion | B |
| Period (P) | 101.606±0.003 d |
| Semi-major axis (a) | ≥26.4±0.2 Gm |
| Eccentricity (e) | 0.117±0.007 |
| Periastronepoch (T) | 2,442,478.0±0.8 HJD |
| Semi-amplitude (K1) (primary) | 19.0±0.1 km/s |
| Orbit[5] | |
| Primary | AB |
| Companion | C |
| Period (P) | 3,385±7 d |
| Semi-major axis (a) | 0.074±0.001" (407±6 Gm) |
| Eccentricity (e) | 0.073±0.010 |
| Inclination (i) | 104.6±0.5° |
| Periastronepoch (T) | 2,442,880±40 HJD |
| Argument of periastron (ω) (secondary) | 91.4±4.1° |
| Semi-amplitude (K1) (primary) | 8.5±0.1 km/s |
| Details | |
| A | |
| Mass | 1.99[6] M☉ |
| Radius | 17.0+1.7 −1.6[1] R☉ |
| Luminosity | 236.1+5.9 −5.7[1] L☉ |
| Surface gravity (log g) | 3.41[6] cgs |
| Temperature | 5,488+275 −258[1] K |
| Rotational velocity (v sin i) | 25.3[6] km/s |
| Age | 1.00[6] Gyr |
| Other designations | |
| BD+22°2731,HD 129132,HIP 71729,HR 5472,SAO 83458,WDS J14404+2159AB,GSC 01483-00948[7] | |
| Database references | |
| SIMBAD | data |
HD 129132 is atriple star[5] system in the northernconstellation ofBoötes. It is dimly visible to the naked eye with a combinedapparent visual magnitude of 6.13.[2] The distance to this system is approximately 382 light years based onparallax, and it is drifting further away from theSun with aradial velocity of +1.7 km/s.[1]
This system was found to be aspectroscopic binary by theDominion Astrophysical Observatory in 1923. It was then shown to be a triple star system in 1937 byWilliam E. Harper and Guy H. Blanchet.[8] The inner pair have anorbital period of 101.6 days and aneccentricity of 0.117, with the primary forming the visible component of this pair. The third component forms a visual system with the inner pair, orbiting with a period of 9.27 years and an eccentricity of 0.073.[5][9]
The primary component appears to be an aginggiant star with astellar classification of F4III,[4] although it has also been classed as aG-type main-sequence star of type G0V.[3] It is around a billion years old with twice themass of the Sun.[6] The star has expanded to 17[1] times theSun's radius and is radiating 236[1] times theluminosity of the Sun at aneffective temperature of 5,488 K.[1] It is spinning with aprojected rotational velocity of 25.3 km/s.[6]
