Coma Berenices

Coma Berenices
Coma Berenices
GenitiveComae Berenices
genitive /
SymbolismBerenice's hair
Right ascension11h 58m 25.0885s–13h 36m 06.9433s[1]
Area386 sq. deg. (42nd)
Main stars3
Stars with planets5
Stars brighter than 3.00m0
Stars within 10.00 pc (32.62 ly)1
Brightest starβ Com (4.26m)
Messier objects8
Meteor showersComa Berenicids
Canes Venatici
Ursa Major
Visible at latitudes between +90° and −70°.
Best visible at 21:00 (9 p.m.) during the month of May.

Coma Berenices is an ancient asterism in the northern sky which has been defined as one of the 88 modern constellations. It is located in the fourth galactic quadrant, between Leo and Boötes, and is visible in both hemispheres. Its name means "Berenice's Hair" in Latin and refers to Queen Berenice II of Egypt, who sacrificed her long hair as a votive offering.[2] It was introduced to Western astronomy during the third century BC by Conon of Samos and was further corroborated as a constellation by Gerardus Mercator and Tycho Brahe. Coma Berenices is the only modern constellation named for an historic figure.

Three of the constellation's stars are brighter than magnitude 4.5: Alpha Comae Berenices, Beta Comae Berenices and Gamma Comae Berenices. They form a 45-degree triangle, from which Berenice's imaginary tresses, formed by the Coma Star Cluster, hang. The constellation's brightest star is Beta Comae Berenices, a 4.2-magnitude main sequence star similar to the Sun. Coma Berenices contains the North Galactic Pole and one of the richest known galaxy clusters, the Coma Cluster, part of the Coma Supercluster. Galaxy Malin 1, in the constellation, is the first-known giant low-surface-brightness galaxy. Supernova SN 2005ap discovered in Coma Berenices is the second-brightest known, and SN 1940B was the first observed example of a type II supernova. The star FK Comae Berenices is the prototype of an eponymous class of variable stars. The constellation is the radiant of one meteor shower, Coma Berenicids, which has one of the fastest meteor speeds, up to 65 km/s (40 mps).


Coma Berenices has been recognized as an asterism since the Hellenistic period[3] (or much earlier, according to some authors), and is the only modern constellation named for an historic figure.[4] It was introduced to Western astronomy during the third century BC by Conon of Samos, the court astronomer of Egyptian ruler Ptolemy III Euergetes, to honour Ptolemy's consort, Berenice II.[5] Berenice vowed to sacrifice her long hair as a votive offering if Ptolemy returned safely from battle during the Third Syrian War.[6] Modern scholars are uncertain if Berenice made the sacrifice before or after Ptolemy's return; it was suggested that it happened after Ptolemy's return (around March–June or May 245 BC), when Conon presented the asterism jointly with scholar and poet Callimachus during a public evening ceremony.[7] In Callimachus' poem, Aetia (composed around that time), Berenice dedicated her tresses "to all the gods". In the Latin translation of the poem by the Roman poet Catullus and in Hyginus' De Astronomica, she dedicated her tresses to Aphrodite and placed them in the temple of Arsinoe II (identified after Berenice's death with Aphrodite) at Zephyrium. According to De astronomica, by the next morning the tresses had disappeared. Conon proposed that Aphrodite had placed the tresses in the sky as an acknowledgement of Berenice's sacrifice.[6] Callimachus called the asterism plokamos Berenikēs or bostrukhon Berenikēs in Greek, translated into Latin as "Coma Berenices" by Catullus. Eratosthenes (3rd century BC) called it "Berenice's Hair" and "Ariadne's Hair", considering it part of the constellation Leo.[8] Hipparchus[9] and Geminus recognized it as a distinct constellation,[10] but astronomer Ptolemy did not consider it one of his 48 constellations in the Almagest;[9] he considered it part of Leo,[3] and called it Plokamos.[11]

Sixteenth-century sky map superimposed on a globe
Coma Berenices on Mercator's 1551 celestial globe, in the upper left

Coma Berenices became popular during the 16th century. In 1515, a set of gores by Johannes Schöner labelled the asterism Trica, "hair". In 1536 it appeared on a celestial globe by Caspar Vopel, who is credited with the asterism's designation as a constellation.[12] That year, it also appeared on a celestial map by Petrus Apianus as "Crines Berenices". In 1551, Coma Berenices appeared on a celestial globe by Gerardus Mercator with five Latin and Greek names: Cincinnus, caesaries, πλόκαμος, Berenicis crinis and Trica. Mercator's reputation as a cartographer ensured the constellation's inclusion on Dutch sky globes beginning in 1589.[13]

Tycho Brahe, also credited with Coma's designation as a constellation, included it in his 1602 star catalogue.[3] Brahe recorded fourteen stars in the constellation; Johannes Hevelius increased its number to twenty-one, and John Flamsteed to forty-three. Coma Berenices also appeared in Johann Bayer's 1603 Uranometria, and a few other 17th-century celestial maps followed suit. Coma Berenices and the now-obsolete Antinous are considered the first post-Ptolemaic constellations depicted on a celestial globe.[14] With Antinous, Coma Berenices exemplified a trend in astronomy in which globe- and map-makers continued to rely on the ancients for data. This trend ended at the turn of the 16th century with observations of the southern sky and the work of Tycho Brahe.[13]

Before the 18th century Coma Berenices was known in English by several names, including "Berenice's Bush" and "Berenice's periwig".[15] The earliest known English name, "Berenices haire", dates to 1601.[15][16] By 1702 the constellation was known as Coma Berenices,[17] and appears as such in the 1731 Universal Etymological English Dictionary.

Non-Western astronomy

Coma Berenices was known to the Akkadians as Ḫegala.[18] In Babylonian astronomy a star, known as ḪÉ.GÁL-a-a (translated as "which is before it") or MÚL.ḪÉ.GÁL-a-a, is tentatively considered part of Coma Berenices.[19] It was also argued that Coma Berenices appears in Egyptian Ramesside star clocks as sb3w ꜥš3w, meaning "many stars".[20]

In Arabic astronomy Coma Berenices was known as Al-Dafira and Al-Hulba (translations of Ptolemaic Plokamos), forming the tuft of the constellation Leo[11] and including most of the Flamsteed-designated stars (particularly 12, 13, 14, 16, 17, 18 and 21 Comae Berenices).[21] Ulugh Beg, however, regarded Al-Dafira as consisting of two stars, 7 and 23 Comae Berenices.[22] Presently Al-Dafira is the proper name of Beta Comae Berenices.[23]

In Chinese astronomy, the stars making up Coma Berenices were in two areas: the Supreme Palace enclosure and the Azure Dragon of the East. Eighteen of the constellation's stars were in an area known as Lang wei (seat of the general), part of the Supreme Palace enclosure,[24] The Chinese gave proper names to several stars in the constellation.[24]

The North American Pawnee people depicted Coma Berenices as ten faint stars on a tanned elk-skin star map dated to at least the 17th century.[25] In the South American Kalina mythology, the constellation was known as ombatapo (face).[26]

The constellation was also recognized by several Polynesian peoples. The people of Tonga had four names for Coma Berenices: Fatana-lua, Fata-olunga, Fata-lalo and Kapakau-o-Tafahi.[27] The Boorong people called the constellation Tourt-chinboiong-gherra, and saw it as a small flock of birds drinking rainwater from a puddle in the crotch of a tree.[28] The people of the Pukapuka atoll may have called it Te Yiku-o-te-kiole, although sometimes this name is associated with Ursa Major.[29]

Other Languages
Afrikaans: Berenice se Hare
asturianu: Coma Berenices
Bân-lâm-gú: Thâu-mn̂g-chō
беларуская (тарашкевіца)‎: Валасы Бэрэнікі
brezhoneg: Blev Berenis
Ελληνικά: Κόμη Βερενίκης
español: Coma Berenices
客家語/Hak-kâ-ngî: Heu-fat-chho
한국어: 머리털자리
hrvatski: Berenikina kosa
Bahasa Indonesia: Coma Berenices
íslenska: Bereníkuhaddur
Basa Jawa: Coma Berenices
latviešu: Berenikes Mati
മലയാളം: സീതാവേണി
Bahasa Melayu: Rambut Berenike
Mìng-dĕ̤ng-ngṳ̄: Hâiu-huák-cô̤
日本語: かみのけ座
norsk nynorsk: Berenikes hår
oʻzbekcha/ўзбекча: Veronika sochlari
português: Coma Berenices
Simple English: Coma Berenices
slovenčina: Vlasy Bereniky
srpskohrvatski / српскохрватски: Berenikina kosa
українська: Волосся Вероніки
Tiếng Việt: Hậu Phát
粵語: 后髮座
中文: 后发座