Pisces (constellation)

Pisces is a constellation of the zodiac. Its name is the Latin plural for fish. It lies between Aquarius to the west and Aries to the east. The ecliptic and the celestial equator intersect within this constellation and in Virgo.

Features

The constellation Pisces as it can be seen by naked eye.

The vernal equinox is currently located in Pisces, due south of ω Psc, and, due to precession, slowly drifting below the western fish towards Aquarius.

Stars

• Van Maanen's Star, at 12.36 magnitude, is located in this constellation, along with others, such as HD 222410, at 7.45 magnitude.
• Al Rischa ("the cord"), otherwise Alpha Piscium (α Psc), 139 lightyears, class A2, apparent magnitude 3.62
• Fum al Samakah ("mouth of the fish"), otherwise Beta Piscium (β Psc), 492 lightyears, class B6Ve, apparent magnitude 4.48
• Linteum ("cord"), otherwise Delta Piscium (δ Psc), 305 lightyears, class K5III, apparent magnitude 4.44
• Kaht (also "cord"), otherwise Epsilon Piscium (ε Psc), 190 lightyears, class K0III, apparent magnitude 4.27
• Revati ("rich"), otherwise Zeta Piscium (ζ Psc), 148 lightyears, class A7IV, apparent magnitude 5.21
• Kullat Nunu ("cord of the fish") or Al Pherg ("pouring point of water"), otherwise Eta Piscium (η Psc), 294 lightyears, class G8III, apparent magnitude 3.62
• Torcular ("thread"), otherwise Omicron Piscium (ο Psc), 258 lightyears, class K0III, apparent magnitude 4.2
• Vernalis (referring to the vernal equinox), otherwise Omega Piscium (ω Psc), 106 lightyears, class F4IV, apparent magnitude 4.03

Deep-sky objects

M74 is a loosely wound (type Sc) spiral galaxy in Pisces, found at a distance of 30 million light years (redshift 0.0022). It has many clusters of young stars and the associated nebulae, showing extensive regions of star formation. It was discovered by Pierre Méchain, a French astronomer, in 1780. A type II-P supernova was discovered in the outer regions of M74 by Robert Evans in June 2003; the star that underwent the supernova was later identified as a red supergiant with a mass of 8 solar masses.^[1]

NGC 488 is an isolated face-on prototypical spiral galaxy.

NGC 520 is a pair of colliding galaxies located 90 million lightyears away.

CL 0024+1654 is a massive galaxy cluster that lenses the galaxy behind it, creating arc-shaped images of the background galaxy. The cluster is primarily made up of yellow elliptical and spiral galaxies, at a distance of 3.6 billion light-years from Earth (redshift 0.4), half as far away as the background galaxy, which is at a distance of 5.7 billion light-years (redshift 1.67).^[1]

3C 31 is an active galaxy and radio source in Perseus located at a distance of 237 million light-years from Earth (redshift 0.0173). Its jets, caused by the supermassive black hole at its center, extend several million light-years in both directions, making them some of the largest objects in the universe.^[1]

History and mythology

From Urania's Mirror (1824)

Pisces originates from some composition of the Babylonian constellations Šinunutu₄ "the great swallow" in current western Pisces, and Anunitum the "Lady of the Heaven", at the place of the northern fish. In the first-millennium BC texts known as the Astronomical Diaries, part of the constellation was also called DU.NU.NU (Rikis-nu.mi, "the fish cord or ribbon").^[2]

Pisces is associated with Aphrodite and Eros, who escaped from the monster Typhon by leaping into the sea and transforming themselves into fish.^[3] In order not to lose each other, they tied themselves together with rope. The Romans adopted the Greek legend, with Venus and Cupid acting as the counterparts for Aphrodite and Eros. The knot of the rope is marked by Alpha Piscium (α Psc), also called Al-Rischa ("the cord" in Arabic).^[4]

Pisces in Hevelius' map (1690)

In 1690, the astronomer Johannes Hevelius in his Firmamentum Sobiescianum regarded the constellation Pisces as being composed of four subdivisions:^[5]

• Piscis Boreus (the North Fish): σ – 68 – 65 – 67 – ψ¹ – ψ² – ψ³ – χ – φ – υ – 91 – τ – 82 – 78 Psc.
• Linum Boreum (the North Cord):^[5] χ – ρ,94 – VX(97) – η – π – ο – α Psc.
• Linum Austrinum (the South Cord):^[5] α – ξ – ν – μ – ζ – ε – δ – 41 – 35 – ω Psc.
• Piscis Austrinus (the South Fish):^[5] ω – ι – θ – 7 – β – 5 – κ,9 – λ – TX(19) Psc.

In 1754, the astronomer John Hill proposed to treat part of Pisces as a separate constellation, called Testudo (the Turtle)^[6] 24 – 27 – YY(30) – 33 – 29 Psc.,^[7] centred a natural but faint asterism in which the star 20 Psc is intended to be the head of the turtle. However the proposal was largely neglected by other astronomers with the exception of Admiral Smyth, who mentioned it in his book The Bedford Catalogue, and it is now obsolete.^[8]

Western folklore

The Fishes are also associated with the German legend of Antenteh, who owned just a tub and a crude cabin when he met a magical fish. They offered him a wish, which he refused. However, his wife begged him to return to the fish and ask for a beautiful furnished home. This wish was granted, but her desires were not satisfied. She then asked to be a queen and have a palace, but when she asked to become a goddess, the fish became angry and took the palace and home, leaving the couple with the tub and cabin once again. The tub in the story is sometimes recognized as the Great Square of Pegasus.^[4]

In non-Western astronomy

The stars of Pisces were incorporated into several constellations in Chinese astronomy. Wai-ping ("Outer Enclosure") was a fence that kept a pig farmer from falling into the marshes and kept the pigs where they belonged. It was represented by Alpha, Delta, Epsilon, Zeta, Mu, Nu, and Xi Piscium. The marshes were represented by the four stars designated Phi Ceti. The northern fish of Pisces was a part of the House of the Sandal, Koui-siou.^[4]

Astrology

While the astrological sign Pisces per definition runs from ecliptical longitude 330° to 0, this position is now mostly covered by the constellation of Aquarius, due to the precession from when the constellation and the sign coincided.

References

Sources

• Ridpath, Ian; Tirion, Wil (2007). Stars and Planets Guide (4th ed.). Princeton University Press. ISBN 978-0-691-13556-4. 
• Richard Hinckley Allen, Star Names, Their Lore and Legend, New York, Dover: various dates.
• Staal, Julius D. W. (1988). The New Patterns in the Sky: Myths and Legends of the Stars. The McDonald and Woodward Publishing Company. ISBN 978-0-939923-04-5. 
• Thomas Wm. Hamilton, Useful Star Names, Strategic Books, 2008.

External links

Wikimedia Commons has media related to: Pisces (category)

• The Deep Photographic Guide to the Constellations: Pisces
• Star Tales – Pisces
• Pisces Constellation at Constellation Guide
• Warburg Institute Iconographic Database (over 300 medieval and early modern images of Pisces)

Coordinates: 01^h 00^m 00^s, +15° 00′ 00″