Gamma Pegasi
Encyclopedia
Gamma Pegasi is a star
in the constellation
of Pegasus
. It also has the traditional name Algenib; confusingly however, this name is also used for Alpha Persei
.
The asterism of γ Pegasi and α Andromedae
, in Hindu astronomy, is called Uttara Bhādrapadā
(उत्तरभाद्रपदा) or Uttṛṭṭāti. It is the 26th nakshatra
. In Chinese
, , meaning Wall
(asterism) refers to an asterism consisting of γ Pegasi and α Andromedae
. Consequently, γ Pegasi itself is known as
Gamma Pegasi is a Beta Cephei variable
star that lies at the lower left-hand corner of the Great Square of Pegasus. Its magnitude
varies between +2.78 and +2.89 with a period of 3.6 hours. It is 335 light-year
s distant and belongs to spectral type
B2. It has a total luminosity
of 4000 times that of the Sun
with a radius of 4.5 times solar. The mass of γ Pegasi is 7 to 10 solar mass
es.
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Pegasus
Pegasus (constellation)
Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:...
. It also has the traditional name Algenib; confusingly however, this name is also used for Alpha Persei
Alpha Persei
Alpha Persei is the brightest star in the constellation of Perseus, just outshining the constellation's best known star Algol. It also bears the traditional names Mirfak and Algenib...
.
The asterism of γ Pegasi and α Andromedae
Alpha Andromedae
Alpha Andromedae , which has the traditional names Alpheratz and Sirrah , is the brightest star in the constellation of Andromeda. Located immediately northeast of the constellation of Pegasus, it is the northeastern star of the Great Square of Pegasus...
, in Hindu astronomy, is called Uttara Bhādrapadā
Uttara Bhadrapada
Uttara Bhādrapadā or Uttṛṭṭāti is the twenty-sixth nakshatra in Hindu astrology, corresponding to γ Pegasi and α Andromedae.It is ruled by Shani, the deity identified with the planet Saturn....
(उत्तरभाद्रपदा) or Uttṛṭṭāti. It is the 26th nakshatra
Nakshatra
Nakshatra is the term for lunar mansion in Hindu astrology. A nakshatra is one of 27 sectors along the ecliptic...
. In Chinese
Chinese language
The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...
, , meaning Wall
Wall (Chinese constellation)
The Wall mansion is one of the Twenty-eight mansions of the Chinese constellations. It is one of the northern mansions of the Black Tortoise.- Asterisms :...
(asterism) refers to an asterism consisting of γ Pegasi and α Andromedae
Alpha Andromedae
Alpha Andromedae , which has the traditional names Alpheratz and Sirrah , is the brightest star in the constellation of Andromeda. Located immediately northeast of the constellation of Pegasus, it is the northeastern star of the Great Square of Pegasus...
. Consequently, γ Pegasi itself is known as
Gamma Pegasi is a Beta Cephei variable
Beta Cephei variable
Beta Cephei variables are variable stars which exhibit variations in their brightness due to pulsations of the stars' surfaces. The point of maximum brightness roughly corresponds to the maximum contraction of the star. Typically, Beta Cephei variables change in brightness by 0.01 to 0.3...
star that lies at the lower left-hand corner of the Great Square of Pegasus. Its magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
varies between +2.78 and +2.89 with a period of 3.6 hours. It is 335 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s distant and belongs to spectral type
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
B2. It has a total luminosity
Luminosity
Luminosity is a measurement of brightness.-In photometry and color imaging:In photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI unit for luminance is candela per square metre.The luminosity function...
of 4000 times that of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
with a radius of 4.5 times solar. The mass of γ Pegasi is 7 to 10 solar mass
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
es.