Alpha Mensae
Scientific overview
Alpha Mensae is a yellow dwarf in the constellation Mensa (Mensae), lying about 33.26 light-years from Earth.
Class G. Yellow stars like the Sun. On the main sequence they steadily fuse hydrogen into helium. Such stars have surface temperatures around 5,200–6,000 K and appear yellow to the eye.
Physical properties
| Spectral type | G5V |
| Luminosity class | V |
| Apparent magnitude | 5.08 |
| Absolute magnitude | 5.04 |
| Luminosity (Sun = 1) | 0.842 |
| Colour index (B−V) | 0.714 |
| Distance | 33.26 ly (10.2 pc) |
Values are real catalogue data; fields without a reliable value are omitted, never estimated.
Precision measurements
Astrometry and astrophysics from SIMBAD and Gaia DR3 · Gaia DR3 5264749303462961280
| Parallax | 97.9158 ± 0.0573 mas | SIMBAD · measured |
| Distance | 10.2117 pc | Gaia · estimated |
| Proper motion (RA) | 121.6 mas/yr | SIMBAD · measured |
| Proper motion (Dec) | -212.4 mas/yr | SIMBAD · measured |
| Radial velocity | 36.118 ± 2.000e-4 km/s | SIMBAD · measured |
| Spectral type | G7V | SIMBAD · catalogued |
| Effective temperature | 5495.9 K | Gaia · modeled |
| Radius | 1.0143 R_sun | Gaia · modeled |
| Surface gravity (log g) | 4.3686 log(cm/s^2) | Gaia · modeled |
| Metallicity [M/H] | 0.0765 dex | Gaia · modeled |
| Right ascension (ICRS) | 92.5603 deg | SIMBAD · measured |
| Declination (ICRS) | -74.753 deg | SIMBAD · measured |
Full field-level provenance
- Parallax: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · plx_value · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Distance: ESA Gaia astrometric survey · Gaia EDR3 · Bailer-Jones (2021) · external.gaiaedr3_distance · r_med_geo · row 5264749303462961280 · Bayesian estimate · retrieved 2026-07-11
- Proper motion (RA): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Proper motion (Dec): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · pmdec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2018A&A...616A...7S · direct catalogue measurement · retrieved 2026-07-11
- Spectral type: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · sp_type · 2006AJ....132..161G · catalogue identifier/value · retrieved 2026-07-11
- Effective temperature: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · teff_gspphot · row 5264749303462961280 · model output · retrieved 2026-07-11
- Radius: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · radius_gspphot · row 5264749303462961280 · model output · retrieved 2026-07-11
- Surface gravity (log g): ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · logg_gspphot · row 5264749303462961280 · model output · retrieved 2026-07-11
- Metallicity [M/H]: ESA Gaia astrometric survey · Gaia DR3 · gaiadr3.astrophysical_parameters · mh_gspphot · row 5264749303462961280 · model output · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2020yCat.1350....0G · direct catalogue measurement · retrieved 2026-07-11
measured = direct catalogue value · estimated = Bayesian inference (Bailer-Jones distance) · modeled = model output (Gaia GSP-Phot). Fields a source did not provide are omitted, never invented.
Evolution
A yellow dwarf is a G-type main-sequence star like the Sun. After about ten billion years it will swell into a red giant and finally leave behind a white dwarf.
Location in the sky
Knowledge connections
- In constellationMensa
Related stars in Mensa
Sources
The primary and reference sources this topic draws on.
- HYG DatabaseHYG Database (Hipparcos + Yale Bright Star + Gliese), by D. Nash / astronexus
Aggregated, openly-licensed star catalogue combining Hipparcos, the Yale Bright Star Catalogue, and the Gliese Catalogue of Nearby Stars.
- HipparcosESA Hipparcos space astrometry mission
High-precision parallax, magnitude, and position for ~118,000 stars.