HD 125040
Visual binary star system in the constellation Boötes
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HD 125040 is a visual binary star system in the northern constellation of Boötes. It appears as a dim point of light near the lower limit of perception with the naked eye, having a combined apparent visual magnitude of 6.25.[7] The system is located at a distance of approximately 106 light years from the Sun based on parallax measurements,[12] but is drifting closer with a radial velocity of −7 km/s.[13] It has a high proper motion, traversing the celestial sphere at an angular rate of 0.164 arcseconds yr−1.[14]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Boötes[1] |
| A | |
| Right ascension | 14h 16m 32.84325s[2] |
| Declination | +20° 07′ 18.6542″[2] |
| Apparent magnitude (V) | 6.41[3] |
| B | |
| Right ascension | 14h 16m 32.97162s[4] |
| Declination | +20° 07′ 14.6100″[4] |
| Apparent magnitude (V) | 8.33[5] |
| Characteristics | |
| Spectral type | F8V[6] |
| B−V color index | +0.488[7] |
| Astrometry | |
| Absolute magnitude (MV) | 3.68[1] |
| A | |
| Radial velocity (Rv) | −6.90±0.47[8] km/s |
| Proper motion (μ) | RA: −135.348[2] mas/yr Dec.: −95.322[2] mas/yr |
| Parallax (π) | 30.2106±0.0226 mas[2] |
| Distance | 107.96 ± 0.08 ly (33.10 ± 0.02 pc) |
| B | |
| Proper motion (μ) | RA: −125.557[4] mas/yr Dec.: −87.056[4] mas/yr |
| Parallax (π) | 30.2246±0.0243 mas[4] |
| Distance | 107.91 ± 0.09 ly (33.09 ± 0.03 pc) |
| Orbit[9] | |
| Period (P) | 956.6±299.4 yr |
| Semi-major axis (a) | 3.75±0.75" (122.3±24.4 AU) |
| Eccentricity (e) | 0.53±0.08 |
| Inclination (i) | 134.3±6.9° |
| Longitude of the node (Ω) | 14.1±10.4° |
| Periastron epoch (T) | 1683.9±14.2 |
| Argument of periastron (ω) (secondary) | 72.2±18.5° |
| Details | |
| A | |
| Mass | 1.2[2] M☉ |
| Radius | 1.3[2] R☉ |
| Luminosity | 2.4[2] L☉ |
| Surface gravity (log g) | 4.22[2] cgs |
| Temperature | 6,326[2] K |
| Metallicity [Fe/H] | −0.31[2] dex |
| Rotational velocity (v sin i) | 35.9[10] km/s |
| Age | 2.5[2] Gyr |
| B | |
| Mass | 0.86[4] M☉ |
| Radius | 0.81[4] R☉ |
| Luminosity | 0.42[4] L☉ |
| Surface gravity (log g) | 4.53[4] cgs |
| Temperature | 5,260[4] K |
| Metallicity [Fe/H] | −0.17[4] dex |
| Age | 5.2[4] Gyr |
| Other designations | |
| BD+20°2954, HD 125040, HIP 69751, HR 5346, SAO 83259, WDS J14165+2007AB[11] | |
| Database references | |
| SIMBAD | data |
| A | |
| B | |
This was first reported to be a double by J. F. W. Herschel in 1830. The stars orbit each other with a semi-major axis of 122 AU, a period of roughly 956.6 years, and an eccentricity of 0.53. They have a combined mass about double that of the Sun.[9] The combined spectral type is of an F-type main-sequence star with a stellar classification of F8V;[6] the brighter primary star has a spectral class of F6V.[15] The system is a source for X-ray emission.[16]