Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Lupus |
Right ascension | 15h 56m 53.49808s[1] |
Declination | −33° 57′ 58.0129″[1] |
Apparent magnitude (V) | 5.114[2] |
Characteristics | |
Spectral type | A3 V[3] |
U−B color index | 0.069[2] |
B−V color index | 0.116[2] |
Astrometry | |
Radial velocity (Rv) | −10.0±4.2[4] km/s |
Proper motion (μ) | RA: +23.27[1] mas/yr Dec.: −37.85[1] mas/yr |
Parallax (π) | 23.60 ± 3.48 mas[1] |
Distance | approx. 140 ly (approx. 42 pc) |
Details | |
Mass | 2.01[5] M☉ |
Luminosity | 12[6] L☉ |
Surface gravity (log g) | 4.14±0.14[5] cgs |
Temperature | 9,206±313[5] K |
Rotational velocity (v sin i) | 78[5] km/s |
Age | 237[5] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Xi1 Lupi (ξ1 Lup, ξ1 Lupi) is a probable binary star[8] in the southern constellation of Lupus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.1,[2] and forms a visual double star with Xi2 Lupi. Based upon an annual parallax shift of 23.60[1] mas as seen from Earth, it is located around 140 light-years from the Sun. It is a member of the Upper Scorpius sub-group of the nearby Sco OB2 association.[9]
This star shows periodic radial velocity variations that can be best explained as a spectroscopic binary system.[8] The visible component is an A-type main-sequence star with a stellar classification of A3 V.[3] It has twice[5] the mass of the Sun and shines with about 12[6] times the Sun's luminosity from its outer atmosphere at an effective temperature of 9,206 K.[5] The star is an estimated 237 million years old and is spinning with a projected rotational velocity of 78 km/s.[5]