HD 142
HD 142 is a wide binary star system in the southern constellation of Phoenix. The main component has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.7. The system is located at a distance of 85.5 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +6 km/s.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Phoenix |
| HD 142 A | |
| Right ascension | 00h 06m 19.1754s |
| Declination | –49° 04′ 30.6741″ |
| Apparent magnitude (V) | 5.711±0.003 |
| HD 142 B | |
| Right ascension | 00h 06m 19.1480s |
| Declination | –49° 04′ 34.9177″ |
| Apparent magnitude (V) | +11.5 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | F7V + K8.5-M1.5 |
| B−V color index | 0.519±0.011 |
| Astrometry | |
| HD 142 A | |
| Radial velocity (Rv) | 5.76±0.12 km/s |
| Proper motion (μ) | RA: 575.099±0.017 mas/yr Dec.: −40.874±0.024 mas/yr |
| Parallax (π) | 38.1945 ± 0.0355 mas |
| Distance | 85.39 ± 0.08 ly (26.18 ± 0.02 pc) |
| Absolute magnitude (MV) | 3.66±0.02 |
| HD 142 B | |
| Proper motion (μ) | RA: 566.984±0.023 mas/yr Dec.: −17.387±0.027 mas/yr |
| Parallax (π) | 38.2306 ± 0.0349 mas |
| Distance | 85.31 ± 0.08 ly (26.16 ± 0.02 pc) |
| Details | |
| HD 142 A | |
| Mass | 1.25±0.10 M☉ |
| Radius | 1.41±0.11 R☉ |
| Luminosity | 2.9 L☉ |
| Surface gravity (log g) | 4.34±0.14 cgs |
| Temperature | 6,338±46 K |
| Metallicity [Fe/H] | 0.03±0.04 dex |
| Rotational velocity (v sin i) | 9.58±0.74 km/s |
| Age | 2.5 Gyr |
| HD 142 B | |
| Mass | 0.54 M☉ |
| Other designations | |
| HD 142A: CD−49°14337, HD 142, HIP 522, HR 6, SAO 214963, WDS J00063-4905A | |
| HD 142B: CD−49°14337B, WDS J00063-4905B, NLTT 218, 2MASS J00061919-4904348 | |
| Database references | |
| SIMBAD | data |
The primary component is an F-type main-sequence star with a stellar classification of F7V, which indicates it is undergoing core hydrogen fusion. It is an estimated 2.5 billion years old and is spinning with a projected rotational velocity of 10 km/s. The star has 1.25 times the mass of the Sun and 1.4 times the Sun's radius. It is radiating 2.9 times the luminosity of the Sun from its photosphere at an effective temperature of 6,338 K.
A magnitude 11.5 companion star was detected in 1894 making this a binary star system. The binary companion was confirmed to be gravitationally bound in 2007 and determined to be a red dwarf of spectral type K8.5-M1.5 with 54% of the Sun's mass. The pair have a projected separation of 120.6 AU.