| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 14h51m 38.30289s[1] |
| Declination | −43° 34′ 31.2965″[1] |
| Apparent magnitude (V) | 4.323[2] (4.84 + 5.27)[3] |
| Characteristics | |
| Spectral type | B5 IV[3] |
| U−B color index | −0.620[2] |
| B−V color index | −0.159[2] |
| Astrometry | |
| Radial velocity (Rv) | +7.30±0.74[4] km/s |
| Proper motion (μ) | RA: −25.20[1] mas/yr Dec.: −27.13[1] mas/yr |
| Parallax (π) | 8.07 ± 0.59 mas[1] |
| Distance | 400 ± 30 ly (124 ± 9 pc) |
| Absolute magnitude (MV) | −1.2±0.3[5] |
| Details | |
| Mass | 5.7±0.2[5] M☉ |
| Radius | 3.5[5] R☉ |
| Luminosity | 1,260[5] L☉ |
| Surface gravity (log g) | 4.1±0.1[5] cgs |
| Temperature | 18,000[6] K |
| Rotational velocity (v sin i) | 25[6] km/s |
| Other designations | |
ο Lup, CD−43° 9391, HD 130807, HIP 72683, HR 5528, SAO 225248.[7] | |
| Database references | |
| SIMBAD | data |
Omicron Lupi (ο Lup) is a binary star[3] in the southern constellationofLupus. It is a visible to the naked eye with a combined apparent visual magnitude of 4.323.[2] Based upon an annual parallax shift of 8.07 mas as seen from Earth,[1] it is located around 400 light-years from the Sun, give or take 30 light-years. At that distance, the visual magnitude of the system is diminished by an extinction factorof0.13±0.01 due to interstellar dust.[5] It is a member of the Upper Centaurus–Lupus[8] subgroup of the nearby Scorpius–Centaurus association.[6]
This is a visual binary star system with the components having an angular separation of 0.1 arcsecond.[8] The primary, component A, is a magnitude 4.84 B-type subgiant star with a stellar classification of B5 V.[3] It displays radial velocity variations indicating it has an unseen second companion orbiting at a separation of at least 17 AU with a period of 27 years or more.[6] The spectrum of the primary displays a Zeeman effect indicating a magnetic field with a strength ranging from −94 to 677 G.[6] The visible companion, component B, has a visual magnitude of 5.27.[3]
