HD 113703
HD 113703, also known by the Bayer designation f Centauri, is a multiple star system in the southern constellation of Centaurus. The combined apparent visual magnitude of this system is +4.71, which is sufficient to make it faintly visible to the naked eye. The distance to this system is approximately 400 light years based on parallax measurements. It is a member of the Lower Centaurus Crux subgroup of the Scorpius–Centaurus association.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 13h 06m 16.70s |
| Declination | −48° 27′ 47.8″ |
| Apparent magnitude (V) | +4.71 |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | B4V + K0Ve |
| U−B color index | −0.562 |
| B−V color index | −0.148±0.006 |
| Astrometry | |
| Radial velocity (Rv) | +6.0±4.2 km/s |
| Proper motion (μ) | RA: −29.558 mas/yr Dec.: −15.692 mas/yr |
| Parallax (π) | 8.1592 ± 0.1559 mas |
| Distance | 400 ± 8 ly (123 ± 2 pc) |
| Absolute magnitude (MV) | −0.68 |
| Details | |
| f Cen Aa | |
| Mass | 4.39 M☉ |
| Surface gravity (log g) | 3.99 cgs |
| Temperature | 14,769 K |
| Rotational velocity (v sin i) | 140±7 km/s |
| Age | 92 Myr |
| f Cen C | |
| Mass | 0.9 M☉ |
| Luminosity | 0.49 L☉ |
| Temperature | 5,020 K |
| Age | 50 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary of f Centauri is a blue-white hued B-type main-sequence star with a stellar classification of B4V. It is a young star with an age estimated at around 92 million years, and is spinning rapidly with a projected rotational velocity of 140 km/s. A close companion with a K magnitude of 9.16, designated component C, was detected in 2002 at an angular separation of 1.55″. In 2013, a spectroscopic companion to the primary was observed using long baseline interferometry, with the two being designated components Aa and Ab.
A faint, magnitude 10.8 companion, component B, was first reported by J. F. W. Herschel in 1836. As of 2015, it was located at a separation of 11.6″ along a position angle of 78°. This is a K-type star with a class of K0Ve, showing emission in the Calcium H and K lines. It is a known BY Draconis variable star with the designation V1155 Centauri. It shares a common space motion with the primary, indicating a probable physical relationship, and its Gaia Data Release 3 parallax of 7.965″±0.018″ suggests a distance of 409 light years. The star shows a strong overabundance in lithium, which demonstrates its young age. It is about 0.8 magnitudes above zero age main sequence and thus is still contracting as a post-T Tauri star. X-ray emission has been detected from this star.