Zeta Geminorum
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Gemini |
| Right ascension | 07h 04m 06.53079s |
| Declination | +20° 34′ 13.0739″ |
| Apparent magnitude (V) | 3.93 (3.68 to 4.16) |
| Characteristics | |
| Spectral type | F7Ib to G3Ib |
| U−B color index | +0.55 |
| B−V color index | 0.88 |
| Variable type | Classical Cepheid |
| Astrometry | |
| Radial velocity (Rv) | +6.7 km/s |
| Proper motion (μ) | RA: −7.29 mas/yr Dec.: −0.41 mas/yr |
| Parallax (π) | 2.78±0.18 mas |
| Distance | 1,120 ly (368 pc) |
| Absolute magnitude (MV) | -3.99 |
| Details | |
| Mass | 7.7 ± 0.3 M☉ |
| Radius | 72±3 R☉ |
| Luminosity | 4,413±332 L☉ |
| Surface gravity (log g) | 1.9 cgs |
| Temperature | 5,260–5,780 K |
| Metallicity [Fe/H] | 0.16 dex |
| Rotational velocity (v sin i) | 19 km/s |
| Age | 70 ± 25 Myr |
| Other designations | |
| Mekbuda, ζ Gem, 43 Gem, BD+20°1687, FK5 269, HD 52973, HIP 34088, HR 2650, SAO 79031, WDS J07041+2034A | |
| Database references | |
| SIMBAD | data |
Zeta Geminorum (ζ Geminorum, abbreviated Zeta Gem, ζ Gem) is a bright star with cluster components, distant optical components and a likely spectroscopic partner in the zodiac constellation of Gemini — in its south, on the left 'leg' of the twin Pollux. It is a classical Cepheid variable star, of which over 800 have been found in our galaxy. As such its regular pulsation and luminosity (proven in its class to correspond) and its relative proximity means the star is a useful calibrator in computing the cosmic distance ladder. Based on parallax measurements, it is approximately 1,200 light-years from the Sun.
Zeta Geminorum is the primary or 'A' component of a multiple star system designated WDS J07041+2034. It bears traditional name Mekbuda, usually anglicised to /mɛkˈbjuːdə/.