HD 107148
HD 107148 is a wide binary star system in the constellation of Virgo. A pair of exoplanets have been confirmed in orbit around the brighter star. This system is located at a distance of 161 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of 25.2 K. Although having an absolute magnitude of 4.47, at that range the system is too faint to be visible with the naked eye, having an apparent visual magnitude of 8.01.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 19m 13.491s |
| Declination | −03° 19′ 11.24″ |
| Apparent magnitude (V) | 8.01 |
| Characteristics | |
| Evolutionary stage | main sequence + white dwarf |
| Spectral type | G5V + DA |
| B−V color index | 0.707±0.013 |
| Astrometry | |
| Radial velocity (Rv) | 25.244±0.0005 km/s |
| Proper motion (μ) | RA: −54.565 mas/yr Dec.: −47.376 mas/yr |
| Parallax (π) | 20.248 ± 0.0283 mas |
| Distance | 161.1 ± 0.2 ly (49.39 ± 0.07 pc) |
| Absolute magnitude (MV) | 4.47 |
| Position (relative to HD 107148 A) | |
| Component | HD 107148 B |
| Epoch of observation | 2009 |
| Angular distance | 34.9″ |
| Position angle | 174.7° |
| Projected separation | 1,790 AU |
| Details | |
| HD 107148 A | |
| Mass | 1.1±0.1 M☉ |
| Radius | 1.15±0.03 R☉ |
| Luminosity | 1.34±0.05 L☉ |
| Surface gravity (log g) | 4.35±0.03 cgs |
| Temperature | 5,789±36 K |
| Metallicity [Fe/H] | 0.33±0.09 dex |
| Rotational velocity (v sin i) | 1.22±0.20 km/s |
| Age | 4±1 Gyr |
| HD 107148 B | |
| Mass | 0.6 M☉ |
| Temperature | 6250±250 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
The brighter primary member, designated component A, has a spectrum that presents as a G-type main-sequence star, a yellow dwarf, with a stellar classification of G5V. The star is about 4 billion years old and is spinning with a projected rotational velocity of 1.2 km/s. Based on the abundance of iron, a measure of the star's metallicity, it is twice as enriched with heavy elements than the Sun. The star exhibits a magnetic activity cycle with a period around 6 years. It has 1.1 times the mass of the Sun and 1.15 times the Sun's radius. HD 107148 is radiating 1.34 times the luminosity of the Sun from its photosphere at an effective temperature of 5,789 K.
In 2012, a comoving white dwarf stellar companion HD 107148 B was detected at projected separation of 1,790 AU, and was confirmed in 2014. It is a 0.6 M☉ remnant core of the former 1.8±0.2 M☉ star with a cooling age of 2.1±0.3 Gyr. This was formerly the primary component of this system before it ejected much of its mass.