Beta Sextantis, Latinized from β Sextantis, is a variable star in the equatorial constellation of Sextans. With an apparent visual magnitude of 5.07,[2] it is faintly visible to the naked eye on a dark night. According to the Bortle scale, it can be viewed from brighter lit suburban skies. The distance to this star, based upon an annual parallax shift of 8.96 mas,[1] is around 364 light years.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Sextans |
| Right ascension | 10h 30m 17.48s[1] |
| Declination | −00° 38′ 13.30″[1] |
| Apparent magnitude (V) | 5.07[2] |
| Characteristics | |
| Spectral type | B6 V[3] or B5 IV/V[4] |
| U−B color index | −0.51[2] |
| B−V color index | −0.14[2] |
| Variable type | α2 CVn[5] |
| Astrometry | |
| Radial velocity (Rv) | 11.6±2.8[6] km/s |
| Proper motion (μ) | RA: −38.805[1] mas/yr Dec.: −24.290[1] mas/yr |
| Parallax (π) | 8.9613 ± 0.2448 mas[1] |
| Distance | 364 ± 10 ly (112 ± 3 pc) |
| Absolute magnitude (MV) | −0.38[7] |
| Details | |
| Radius | 3.2[8] R☉ |
| Luminosity | 184[9] L☉ |
| Surface gravity (log g) | 4.21[10] cgs |
| Temperature | 14,570[10] K |
| Metallicity [Fe/H] | 0.19[10] dex |
| Rotational velocity (v sin i) | 85±4[10] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
This star served as a primary standard in the MK spectral classification system with a stellar classification of B6 V,[3] indicating that it is a B-type main sequence star. However, Houk and Swift (1999) list a classification of B5 IV/V, suggesting it may be transitioning into a subgiant star.[4] It has served as a uvby photometric standard, but is also categorized as an Alpha2 Canum Venaticorum variable[5] with a suspected period of 15.4 days. This lengthy a period conflicts with a relatively high projected rotational velocity of 85 km/s, leaving the explanation for the variance unresolved.[10][3]