Alpha Comae Berenices
Encyclopedia
Alpha Comae Berenices (Alpha Com, α Com, α Comae Berenices) is a star
in the constellation
Coma Berenices
(Berenice's Hair). Although it has the Bayer designation
"alpha", at magnitude
4.32 it is actually fainter than Beta Comae Berenices
. It has the traditional name Diadem
. It is said to represent the crown worn by Queen Berenice. A name occasionally seen is Al Dafirah, from the Arabic الضفيرة ađ̧-đ̧afīrah "the braid".
In Chinese
, , meaning Left Wall of Supreme Palace Enclosure
, refers to an asterism consisting of α Comae Berenices, η Virginis
, γ Virginis
, δ Virginis
and ε Virginis
. Consequently, α Comae Berenices itself is known as , representing , meaning The First Eastern General. 東上將 (Dōngshǎngjiāng), westernized into Shang Tseang, but the name Shang Tseang was designated for "v Comae Berenices" by R.H. Allen and the meaning is "a Higher General"
, with almost equal components of magnitudes 5.05m and 5.08m orbiting each other with a period of 25.87 years. The system, estimated to be 65 light years
distant, appears so nearly "edge-on" from the Earth that the two stars appear to move back-and-forth in a straight line with a maximum separation of only 0.7 arcsec. It is not known whether eclipses occur between the two components at periastron (minimum separation)—the only such passage since the determination of the orbit, in 1990, was not quantitatively followed by observers.
The mean separation between them is approximately 10 A.U., about the distance between the Sun and Saturn
.
, CCDM J13100+1732C, of apparent magnitude 10.2, located 89 arcseconds away.
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....
Coma Berenices
Coma Berenices
Coma Berenices is a traditional asterism that has since been defined as one of the 88 modern constellations. It is located near Leo, to which it formerly belonged, and accommodates the North Galactic Pole...
(Berenice's Hair). Although it has the Bayer designation
Bayer designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name...
"alpha", at 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...
4.32 it is actually fainter than Beta Comae Berenices
Beta Comae Berenices
Beta Comae Berenices is a main sequence dwarf star in the constellation of Coma Berenices. It is located at a distance of about 30 light years. The Greek letter beta usually indicates that the star has the second highest visual magnitude in the constellation...
. It has the traditional name Diadem
Diadem (personal wear)
A diadem is a type of crown, specifically an ornamental headband worn by Eastern monarchs and others as a badge of royalty. The word derives from the Greek "διάδημα" , "band" or "fillet", from "διαδέω" , "I bind round", or "I fasten"....
. It is said to represent the crown worn by Queen Berenice. A name occasionally seen is Al Dafirah, from the Arabic الضفيرة ađ̧-đ̧afīrah "the braid".
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 Left Wall of Supreme Palace Enclosure
Supreme Palace enclosure
Tai Wei Yuan, the Supreme Palace Enclosure , is one of the San Yuan or Three enclosures. Stars and constellations of this group are visible during autumn in the Northern Hemisphere .-Asterisms:The asterisms are :...
, refers to an asterism consisting of α Comae Berenices, η Virginis
Eta Virginis
Eta Virginis is a star in the constellation Virgo. It has the traditional name Zaniah .Zaniah is about 204 light years distant from the Sun, and has apparent magnitude +3.9 and is of spectral type A2IV....
, γ Virginis
Gamma Virginis
Gamma Virginis is a star in the constellation Virgo. It has the traditional names Porrima, Postvarta and Arich....
, δ Virginis
Delta Virginis
Delta Virginis is a red giant star in the constellation Virgo. It also has the traditional name Auva.It has a spectral type of M3-III, and an magnitude of 3.38, bright enough to be seen with the naked eye...
and ε Virginis
Epsilon Virginis
Epsilon Virginis is a star in the constellation Virgo. It has the traditional name Vindemiatrix, which comes from Greek through Latin and means Grape Gatherer....
. Consequently, α Comae Berenices itself is known as , representing , meaning The First Eastern General. 東上將 (Dōngshǎngjiāng), westernized into Shang Tseang, but the name Shang Tseang was designated for "v Comae Berenices" by R.H. Allen and the meaning is "a Higher General"
Properties
It is a binary starBinary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
, with almost equal components of magnitudes 5.05m and 5.08m orbiting each other with a period of 25.87 years. The system, estimated to be 65 light years
Light Years
Light Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....
distant, appears so nearly "edge-on" from the Earth that the two stars appear to move back-and-forth in a straight line with a maximum separation of only 0.7 arcsec. It is not known whether eclipses occur between the two components at periastron (minimum separation)—the only such passage since the determination of the orbit, in 1990, was not quantitatively followed by observers.
The mean separation between them is approximately 10 A.U., about the distance between the Sun and Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
.
Visual companion
The binary star has a visual companionDouble star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
, CCDM J13100+1732C, of apparent magnitude 10.2, located 89 arcseconds away.