| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h12m 17.09595s[1] |
| Declination | −52° 05′ 57.2919″[1] |
| Apparent magnitude (V) | 3.41[2] (3.50 + 6.74)[3] |
| Characteristics | |
| Spectral type | G7 III[4] |
| U−B color index | +0.66[2] |
| B−V color index | +0.92[2] |
| Astrometry | |
| Radial velocity (Rv) | −10.0±0.6[5] km/s |
| Proper motion (μ) | RA: −112.92[1] mas/yr Dec.: −71.18[1] mas/yr |
| Parallax (π) | 27.80 ± 0.15 mas[1] |
| Distance | 117.3 ± 0.6 ly (36.0 ± 0.2 pc) |
| Absolute magnitude (MV) | 0.65[6] |
| Details | |
| ζ Lup A | |
| Mass | 2.29[6] M☉ |
| Radius | 10[7] R☉ |
| Luminosity | 53[8] L☉ |
| Surface gravity (log g) | 3.01[9] cgs |
| Temperature | 5,335[8] K |
| Metallicity [Fe/H] | 0.00±0.02[9] dex |
| Other designations | |
ζ Lup, CD−51°8830, FK5 558, GJ 9512 A, HD 134505, HIP 74395, HR 5649, SAO 242304, WDS J15123-5206A[10] | |
| Database references | |
| SIMBAD | data |
ζ Lupi (Latinised as Zeta Lupi) is the brighter component of a wide double star in the constellation Lupus, consisting of an orange-hued primary and a fainter secondary with a golden-yellow hue.[11] It is visible to the naked eye with a combined apparent visual magnitude of 3.41.[2] Based upon an annual parallax shift of 27.80[1] mas as seen from Earth, it is located 117.3 light-years from the Sun.
This is a probable binary star system.[12] As of 2013, the pair had an angular separation of 71.20 arcseconds along a position angle of 249°.[3] The primary, component A, is an evolved G-type giant star with a visual magnitude of 3.50[3] and a stellar classification of G7 III.[4] This is a red clump star, indicating that it is generating energy through the thermonuclear fusion of helium in its core region.[13] Its measured angular diameteris2.55±0.13 mas,[14] which, at the estimated distance of Zeta Lupi, yields a physical size of about 10 times the radius of the Sun.[7]
The secondary, component B, has a visual magnitude of 6.74.[3]
