Epsilon Pegasi

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Epsilon Pegasi
Observation data
Epoch J2000
Constellation
(pronunciation)
Pegasus
Right ascension 21h 44m 11.2s
Declination +09° 52′ 30.0″
Apparent magnitude (V) 2.38
Characteristics
Spectral type K2 Ib
U-B color index 1.7
B-V color index 1.52
Variable type irregular/flare
Astrometry
Radial velocity (Rv) 5 km/s
Proper motion (μ) RA: 30.02 mas/yr
Dec.: 1.38 mas/yr
Parallax (π) 4.85 ± 0.84 mas
Distance approx. 700 ly
(approx. 210 pc)
Absolute magnitude (MV) -4.19
Details
Mass 10-11 M
Radius 150 R
Luminosity 6,700 L
Temperature 4,460 K
Metallicity ?
Rotation <17 km/s.
Age ? years
Other designations
Enif, Enf, Enir, Al Anf, Os Pegasi, Fom, 8 Peg, HR 8308, BD +09°4891, HD 206778, SAO 127029, FK5 815, HIP 107315.

Epsilon Pegasi (ε Peg / ε Pegasi) is a star in the constellation Pegasus. It also has the traditional name Enif.

It is fairly average for an orange supergiant star, well into the later stages of its stellar evolution and as such may be considered a dying star. Enif likely only has a few million years left to go, although it is unknown whether it will explode in a supernova or die off as a rare neon-oxygen white dwarf, due to its mass straddling the dividing line between stars destined to explode or not. Enif has been observed to brighten radically upon a few occasions, giving rise to the theory that it (and possibly other supergiants) erupt in massive flares that dwarf those of our own Sun.

The word Enif is derived from the Arabic word for nose, due to its position as the muzzle of Pegasus.

[edit] See also