9 Pegasi (9 Peg) is a supergiant

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

Pegasus Pegasus (; ) is a winged horse in Greek mythology, usually depicted as a white stallion. He was sired by Poseidon, in his role as horse-god, and foaled by the Gorgon Medusa. Pegasus was the brother of Chrysaor, both born from Medusa's blood w ...

. Its

apparent magnitude Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

is 4.35. 9 Pegasi is defined and used as an MK standard star for the spectral type G5 Ib. It is a yellow supergiant nearly two thousand times more luminous than the sun and sixty times larger. It has been reported to be slightly variable and is listed in the New Catalogue of Suspected Variable Stars with a magnitude range of 4.20 to 4.35. 9 Pegasi does not have a

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek alphabet, Greek or Latin letter followed by the genitive case, genitive form of its parent constellation's Latin name. The original list of Bayer design ...

although it is brighter than several stars in Pegasus that do such as τ, φ, and σ Pegasi. It is the 9th star numbered by Flamsteed in order of

right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the equinox (celestial coordinates), March equinox to the (hour circle of the) point in questio ...

. In the 1795 French-language Fortin-Flamsteed edition of the Atlas Coelestis, 9 Pegasi is labelled with the letter "g".

References

{{DEFAULTSORT:9 Pegasi Pegasus (constellation) G-type supergiants Suspected variables Pegasi, 09 8313 206859 107348 BD+16 4582