Observation data Epoch J2000 Equinox J2000 |
|
---|---|
Constellation | Pegasus |
Right ascension | 21h 44m 11.15614s |
Declination | +09° 52′ 30.0311″ |
Apparent magnitude (V) | 2.399 |
Characteristics | |
Spectral type | K2 Ib |
U−B color index | +1.722 |
B−V color index | +1.527 |
Variable type | LC |
Astrometry | |
Radial velocity (Rv) | 3.39 ± 0.06 km/s |
Proper motion (μ) |
RA: +26.92 mas/yr Dec.: +0.4 mas/yr |
Parallax (π) | 4.73 ± 0.17mas |
Distance | 690 ± 20 ly (211 ± 8 pc) |
Absolute magnitude (MV) | –4.142 |
Details | |
Mass | 11.7 ± 0.8 M☉ |
Radius | 185 R☉ |
Luminosity | 3895 L☉ |
Luminosity (bolometric) | 12,250 L☉ |
Surface gravity (log g) | 1.01 cgs |
Temperature | 4,379 K |
Metallicity [Fe/H] | –0.04 dex |
Rotational velocity (v sin i) | 8 km/s |
Age | 20.0 ± 4.5 Myr |
Other designations | |
Database references | |
SIMBAD | data |
Epsilon Pegasi (ε Pegasi, abbreviated Epsilon Peg, ε Peg), also named Enif (EE-nif), is the brightest star in the northern constellation of Pegasus. With an apparent visual magnitude of 2.4, this is a second-magnitude star that is readily visible to the naked eye. The distance to this star can be estimated using parallax measurements from the Hipparcos astrometry satellite, yielding a value of around 690 light-years (210 parsecs).
ε Pegasi (Latinised to Epsilon Pegasi) is the star's Bayer designation.
It bore the traditional name Enif derived from the Arabic word for 'nose', due to its position as the muzzle of Pegasus. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Enif for this star.
Other traditional names for the star include Fom al Feras, Latinised to Os Equi. In Chinese, 危宿 (Wēi Sù), meaning Rooftop (asterism), refers to an asterism consisting of Epsilon Pegasi, Alpha Aquarii and Theta Pegasi. Consequently, Epsilon Pegasi itself is known as 危宿三 (Wēi Sù sān, English: the Third Star of Rooftop.)