HD 126129 and HD 126128

HD 126129 and HD 126128
Observation data
Epoch J2000      Equinox J2000
Constellation Boötes
HD 126129
Right ascension 14h 23m 22.69548s
Declination +08° 26 47.8266
Apparent magnitude (V) 5.04
HD 126128
Right ascension 14h 23m 22.59914s
Declination +08° 26 41.6666
Apparent magnitude (V) 6.74 (7.50 + 7.70)
Characteristics
HD 126129
Evolutionary stage main sequence
Spectral type A0V
U−B color index −0.08
B−V color index −0.02
HD 126128
Spectral type F0V + F2V
U−B color index −0.01
B−V color index +0.43
Astrometry
HD 126129
Radial velocity (Rv)−22.6 km/s
Proper motion (μ) RA: −75.188 mas/yr
Dec.: −9.265 mas/yr
Parallax (π)14.3216±0.1123 mas
Distance228 ± 2 ly
(69.8 ± 0.5 pc)
HD 126128
Radial velocity (Rv)−17.6 km/s
Proper motion (μ) RA: −83.783 mas/yr
Dec.: −4.601 mas/yr
Parallax (π)9.7572 ± 0.7363 mas
Distance330 ± 30 ly
(102 ± 8 pc)
Orbit
PrimaryB
CompanionC
Period (P)40.0 yr
Semi-major axis (a)0.24″
Eccentricity (e)0.25
Inclination (i)42°
Details
HD 126129
Mass2.4 M
Radius2.4 R
Luminosity47 L
Surface gravity (log g)3.95 cgs
Temperature9,729 K
Rotational velocity (v sin i)133 km/s
Age381 Myr
B
Mass1.37 M
Rotational velocity (v sin i)133 km/s
C
Mass1.31 M
Other designations
BD+09°2882, HIP 70327, ADS 9247, WDS J14234+0827
HD 126129: HD 126129, HR 5386, SAO 120426
HD 126128: HD 126128, HR 5385
Database references
SIMBADdata
HD 126129
HD 126128

HD 126129 and HD 126128 form a triple star in the northern constellation of Boötes. HD 126128 is a very close pair which lies at an angular separation of 6.250 from the brightest member of the trio, HD 126129.

The Hipparcos parallax for the combined triple is 15.17±0.42 mas, suggesting a distance around 215 light years. The Gaia DR3 parallax for HD 126129 (component A) indicates a distance close to 228 light years. Gaia DR3 does not contain a parallax for the BC pair HD 126128, but Gaia DR2 indicates an approximate distance of 330 light years. However, the stars are treated as being related and both are considered members of the IC 2391 supercluster.