Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Leo |
Right ascension | 11h 21m 08.1943s[1] |
Declination | +06° 01′ 45.558″[1] |
Apparent magnitude (V) | 4.046[2] |
Characteristics | |
Spectral type | B9.5 Vs[3] |
U−B color index | –0.12[4] |
B−V color index | –0.06[4] |
Astrometry | |
Radial velocity (Rv) | –5.3[5] km/s |
Proper motion (μ) | RA: –91.76[1] mas/yr Dec.: –12.83[1] mas/yr |
Parallax (π) | 15.24 ± 0.81 mas[1] |
Distance | 210 ± 10 ly (66 ± 3 pc) |
Absolute magnitude (MV) | −0.10[6] |
Details | |
Mass | 2.76[7] M☉ |
Radius | 3.3[8] R☉ |
Luminosity | 133[6] L☉ |
Surface gravity (log g) | 3.83±0.03[9] cgs |
Temperature | 10,250[8] K |
Metallicity [Fe/H] | +0.0[8] dex |
Rotational velocity (v sin i) | 70[10] km/s |
Age | 293[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Sigma Leonis, Latinized from σ Leonis, is a blue-white hued star in the zodiac constellation Leo that is visible to the naked eye with an apparent visual magnitude of 4.0.[2] Its annual parallax shift of 15.24 mas as seen from Earth implies a distance around 210 light years from the Sun. It is moving closer to the Sun with a radial velocity of –5 km/s.[5]
Chini et al. (2012) list this as a single-lined spectroscopic binary system.[3] The visible component has a stellar classification of B9.5 Vs,[3] indicating it is a B-type main-sequence star. It is a suspected magnetic Ap star that shows an abundance anomaly with the element silicon.[12] Sigma Leonis has an estimated 2.76[7] times the mass of the Sun and 3.3[8] times the Sun's radius. It is about 293[7] million years old with a projected rotational velocity of 70 km/s.[10] The star is radiating 133[6] times the Sun's luminosity from its photosphere at an effective temperature of 10,250 K.[8]
In Chinese, 太微右垣 (Tài Wēi Yòu Yuán), meaning Right Wall of Supreme Palace Enclosure, refers to an asterism consisting of σ Leonis, β Virginis, ι Leonis, θ Leonis and δ Leonis.[13] Consequently, the Chinese name for σ Leonis itself is 太微右垣二 (Tài Wēi Yòu Yuán èr, English: the Second Star of Right Wall of Supreme Palace Enclosure.),[14] representing 西上將 (Xīshǎngjiāng), meaning The First Western General.[15] 西上將 (Xīshǎngjiāng), spelled Shang Tseang by R.H. Allen, means "the Higher General".[16]