Pisces (constellation)

Pisces is a large constellation located in the Northern celestial hemisphere. It is a member of the zodiac, which is a belt of constellations along the ecliptic. The name Pisces is the Latin word for "fishes." This constellation sits between Aquarius to the southwest and Aries to the east. It is a very large area of the sky, but it is also quite dim. In fact, it is the second dimmest of all the zodiac constellations. Because the stars are not very bright, it is difficult to see Pisces near major cities due to light pollution.

The constellation holds a special place in our solar system's relationship with the sky. The celestial equator and the ecliptic intersect within its boundaries. This intersection happens at the first point of Aries and the first point of Libra. During the March equinox, the Sun passes directly overhead of the equator at approximately this point in the sky. Due to a process called precession, the March equinox is currently drifting westward. It is moving from its position south of the star Omega Piscium toward Aquarius.

Many distinct stars inhabit the region of Pisces. Alrescha, also known as Alpha Piscium, acts as "the cord" connecting the fishes. It is a variable binary star located 309.8 light-years away. Another notable star is Fumalsamakah, or Beta Piscium, which is 492 light-years away. Some stars in this constellation are quite unique. For example, Gamma Piscium is a star that hosts a discovered exoplanet. Another star, Zeta Piscium, is a quintuple star system, meaning it contains five stars.

One of the most scientifically significant objects in Pisces is Van Maanen's Star. This is the closest-known solitary white dwarf to our Sun. A white dwarf is a very dense, small star. This star has a mass about 67% of the Sun's, but its radius is only 1% of the Sun's. Its outer atmosphere has a temperature of approximately 6,110 K. Because white dwarfs steadily radiate away their heat, scientists use this temperature to estimate age. This star is thought to be around 3 billion years old. It is too faint to be seen with the naked eye.

Beyond individual stars, Pisces contains massive deep-sky objects. The M74 galaxy, known as the Phantom Galaxy, is a spiral galaxy located 30 million light-years away. It was discovered by the French astronomer Pierre Méchain in 1780. This galaxy features many clusters of young stars and regions of star formation. Another object is the active galaxy 3C 31, located 237 million light-years away. It contains a supermassive black hole at its center. This black hole creates massive jets that extend several million light-years in opposite directions.

Humans have shared many stories about these stars throughout history. In Greco-Roman antiquity, the constellation was seen as two fish joined by a cord. Greek legends suggest Aphrodite and her son Eros transformed into fish to escape the monster Typhon. In Roman versions, Venus and Cupid were carried by two fish to safety. Another myth says fish helped hatch a goddess from an egg in the Euphrates River. These fish were then rewarded by being placed in the heavens.

Different cultures have interpreted these stars in various ways. In ancient Mesopotamia, parts of the constellation were called DU.NU.NU, meaning "the fish cord." In Chinese astronomy, the stars were part of different groups, such as a "fence" called Wai-ping. This fence was meant to keep pigs in a marsh. In 1690, the astronomer Johannes Hevelius divided the constellation into four specific parts. He identified a North Fish, a South Fish, and two cords. While some later proposals tried to add a "Turtle" to the area, they were mostly ignored by other astronomers.