Eta Cephei
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 20h 45m 17.37517s |
| Declination | +61° 50′ 19.6142″ |
| Apparent magnitude (V) | 3.426 |
| Characteristics | |
| Spectral type | K0 IV |
| U−B color index | +0.613 |
| B−V color index | +0.918 |
| Astrometry | |
| Radial velocity (Rv) | −87.55±0.11 km/s |
| Proper motion (μ) | RA: +85.993 mas/yr Dec.: +818.451 mas/yr |
| Parallax (π) | 69.5976±0.1279 mas |
| Distance | 46.86 ± 0.09 ly (14.37 ± 0.03 pc) |
| Absolute magnitude (MV) | 2.631 |
| Details | |
| Mass | 1.40±0.14 M☉ |
| Radius | 3.86±0.02 R☉ |
| Luminosity | 8.4±0 L☉ |
| Surface gravity (log g) | 3.30±0.06 cgs |
| Temperature | 5,000±9 K |
| Metallicity [Fe/H] | −0.22±0.02 dex |
| Rotational velocity (v sin i) | 6.79 km/s |
| Age | 2.5±0.3 Gyr |
| Other designations | |
| 3 Cephei, BD+61 2050, FK5 783, HD 198149, HIP 102422, HR 7957, SAO 19019 | |
| Database references | |
| SIMBAD | data |
Eta Cephei (η Cep, η Cephei) is a star in the northern circumpolar constellation of Cepheus. With an apparent visual magnitude of 3.4, this is a third magnitude star that, according to the Bortle Dark-Sky Scale, is readily visible to the naked eye. Parallax measurements put it at a distance of 14.37 parsecs (46.9 light-years) from Earth.