Alpha Mensae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Mensa |
| Right ascension | 06h 10m 14.47261s |
| Declination | −74° 45′ 10.9585″ |
| Apparent magnitude (V) | 5.09 |
| Characteristics | |
| Spectral type | G7 V + M3.5-6.5 V |
| U−B color index | 0.33 |
| B−V color index | 0.72 |
| Astrometry | |
| Radial velocity (Rv) | +36.06±0.12 km/s |
| Proper motion (μ) | RA: +121.596 mas/yr Dec.: −212.411 mas/yr |
| Parallax (π) | 97.9158±0.0573 mas |
| Distance | 33.31 ± 0.02 ly (10.213 ± 0.006 pc) |
| Absolute magnitude (MV) | 5.03 |
| Details | |
| α Men A | |
| Mass | 0.964±0.037 M☉ |
| Radius | 0.960±0.013 R☉ |
| Luminosity | 0.81±0.02 L☉ |
| Surface gravity (log g) | 4.459±0.006 cgs |
| Temperature | 5,569±50 K |
| Metallicity [Fe/H] | 0.11±0.05 dex |
| Rotational velocity (v sin i) | 0.6±0.6 km/s |
| Age | 6.2±1.4 Gyr |
| α Men B | |
| Mass | 0.169±0.006 M☉ |
| Radius | 0.19±0.01 R☉ |
| Temperature | 3,054±44 K |
| Other designations | |
| Hoerikwaggo, α Men, CD−74°294, FK5 239, GJ 231, HD 43834, HIP 29271, HR 2261, SAO 256274, LTT 2490 | |
| Database references | |
| SIMBAD | A |
| B | |
| Exoplanet Archive | data |
| ARICNS | data |
Alpha Mensae, also named Hoerikwaggo, is the brightest star in the constellation Mensa. At a magnitude of 5.09, it is the dimmest lucida (a constellation's brightest star) in the sky, and the second-faintest star labeled "alpha", after Alpha Octantis. Due to its declination, on Earth it is best visible from higher latitudes of the southern hemisphere, yet can also be seen, though low in the sky, from just north of the Equator when near its daily arc's highest point, the culmination. It is 33 light-years away from the Solar System. Alpha Mensae is a G-type main sequence star, forming a binary star system with a red dwarf companion.