HD 154857
HD 154857 is a star with two exoplanetary companions in the southern constellation of Ara. It is too dim to be visible with the naked eye having an apparent visual magnitude of 7.25. The star is located at a distance of 207 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +28 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ara |
| Right ascension | 17h 11m 15.72180s |
| Declination | −56° 40′ 50.8706″ |
| Apparent magnitude (V) | 7.25 |
| Characteristics | |
| Spectral type | G5IV-V |
| B−V color index | 0.699±0.001 |
| Variable type | Constant |
| Astrometry | |
| Radial velocity (Rv) | +28.06±0.15 km/s |
| Proper motion (μ) | RA: 87.585 mas/yr Dec.: −55.891 mas/yr |
| Parallax (π) | 15.7321 ± 0.0385 mas |
| Distance | 207.3 ± 0.5 ly (63.6 ± 0.2 pc) |
| Absolute magnitude (MV) | 3.07 |
| Details | |
| Mass | 1.718+0.03 −0.022 M☉ |
| Radius | 2.1±0.1 R☉ |
| Luminosity | 4.4±0.3 L☉ |
| Surface gravity (log g) | 3.83±0.03 cgs |
| Temperature | 5,740±46 K |
| Metallicity [Fe/H] | −0.26±0.01 dex |
| Rotational velocity (v sin i) | 1.44±0.50 km/s |
| Age | 5.8±0.5 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a G-type star with a stellar classification of G5IV-V. The absolute magnitude of this star is two magnitudes above the main sequence, which suggests that the star is evolving toward the subgiant stage. It is a metal-poor thin disk star approximately six billion years old and is chromopherically quiet although not in a Maunder Minimum state. The star is larger, more massive, and more luminous than the Sun. It is spinning with a projected rotational velocity of 1.4 km/s.