Alpha Pegasi
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- This article is about the star named Markab, for alternate meanings, see Markab.
| Observation data Equinox J2000 |
|
|---|---|
| Constellation | Pegasus |
| Right ascension | 23h 04m 45.7s |
| Declination | +15° 12′ 18.9″ |
| Apparent magnitude (V) | 2.49 |
| Characteristics | |
| Spectral type | B9 III |
| U-B color index | -0.05 |
| B-V color index | -0.04 |
| Variable type | ? |
| Astrometry | |
| Radial velocity (Rv) | -4 km/s |
| Proper motion (μ) | RA: 61.1 mas/yr Dec.: -42.56 mas/yr |
| Parallax (π) | 23.36 ± 0.76 mas |
| Distance | 140 ± 5 ly (43 ± 1 pc) |
| Absolute magnitude (MV) | -0.70 |
| Details | |
| Mass | 4 M☉ |
| Radius | 2.8 R☉ |
| Luminosity | 160 L☉ |
| Temperature | 11,000 K |
| Metallicity | ? |
| Rotation | 1.5 days |
| Age | ? years |
| Other designations | |
Alpha Pegasi (α Peg / α Pegasi) is the third brightest star in the constellation Pegasus (despite its "alpha" designation) and one of the four stars in the asterism known as the Great Square of Pegasus. It also has the traditional name Markab (or Marchab).
Markab is a relatively average star nearing the end of its stellar evolution on the main sequence. Markab will soon enter the helium burning phase of its development, during which it will likely expand into a red giant. Like the Sun, it will probably end its life quietly as a white dwarf.
The name Markab comes from an Arabic phrase المركب الفرس al-markab al-faras, "the saddle of the horse". An alternative name, Mankib, comes from المنكب الفرس al-mankib al-faras, or "the shoulder of the horse".
