Pisces: The Fishes Constellation

Pisces is a large but faint zodiac constellation stretching beneath the Great Square of Pegasus. Despite the challenge of its dim stars, Pisces holds remarkable astronomical significance as the current home of the vernal equinox, the point where the Sun crosses the celestial equator at the start of spring. Trace its subtle shape with StarGlobe.

How to Find Pisces

Finding Pisces is best accomplished using the Great Square of Pegasus as a reference. The constellation wraps around the southeastern and southern corners of the Square. A small ring of stars called the Circlet (or the Western Fish) lies below the Square's southern edge, while a line of stars extends eastward and then northward to form the cord connecting the two fish.

The Circlet is the most distinctive part of Pisces. It is formed by seven stars in a rough oval, though all are fourth magnitude or fainter, requiring at least suburban-quality darkness to see clearly. The second fish lies near the star Alrescha (Alpha Piscium), where the two cords connecting the fish meet in a knot.

Because Pisces is so faint, a bright planet passing through the constellation is often the easiest way to identify its location. Jupiter and Saturn pass through Pisces periodically, temporarily making the region easy to find.

The Stars of Pisces

Eta Piscium is the brightest star in the constellation at magnitude 3.6, a yellow giant about 294 light-years away. Despite being the most luminous member, it is not well known, reflecting the generally faint nature of the constellation.

Alrescha (Alpha Piscium) marks the knot where the two cords tie the fish together. It is a close double star consisting of two white components separated by about 1.8 arcseconds, requiring a moderate telescope and steady seeing to split. The pair orbits with a period of roughly 700 years.

Fum al Samakah (Beta Piscium) and Gamma Piscium are other notable stars. Gamma Piscium, at the southeastern corner of the constellation, is a yellow giant often used as a reference point because it sits near the ecliptic.

Deep Sky Objects

M74 is Pisces's most significant deep sky object, a face-on grand-design spiral galaxy about 32 million light-years away. It is one of the most challenging Messier objects due to its low surface brightness, requiring dark skies and patience to observe. In photographs, M74 reveals beautiful spiral arms, making it one of the most photogenic galaxies in the sky.

NGC 488 is another spiral galaxy in Pisces, brighter and easier to observe than M74. NGC 524 is a lenticular galaxy, and NGC 7541 is an edge-on spiral. These galaxies provide targets for observers with moderate to large telescopes exploring this often-overlooked region of sky.

The Vernal Equinox

The vernal equinox, still called the "First Point of Aries" for historical reasons, currently lies within Pisces due to the slow precession of Earth's axis. The equinox entered Pisces around 68 BCE and will remain there for centuries to come before moving into Aquarius. This makes Pisces the actual "first constellation" of the current astronomical zodiac, even though the traditional system still begins with Aries.

Mythology and Cultural Heritage

In Greek mythology, Pisces represents two fish connected by a cord. The most common version tells of Aphrodite and her son Eros, who transformed into fish and tied themselves together with a cord to escape the monster Typhon. They dove into the Euphrates River to safety, and the two fish were placed among the stars to commemorate the escape.

In Babylonian astronomy, the constellation was associated with the great goddess Anunitum and the god Ea, both water deities. The "two tails" of the constellation represented different aspects of these divine figures. Syrian traditions held that fish from the Euphrates pushed a great egg to shore, from which Aphrodite was born, linking the fish to the goddess of love.

In Hindu astronomy, the last segment of the zodiac corresponds to Revati, associated with wealth and prosperity. The connection between fish and abundance runs through many cultural traditions worldwide.

Best Time to Observe

Pisces is best observed during October and November evenings, when it crosses the meridian high in the sky. The constellation is visible from August through January. Due to its faint stars, a moonless night well away from city lights is essential for tracing the full figure. Even experienced observers sometimes struggle with Pisces under anything less than good conditions.

Neighboring Constellations

Pegasus dominates the sky above Pisces, with Andromeda to the northeast. Aries lies to the east, Aquarius to the south, and Cetus to the southeast. Triangulum sits to the north. Navigate this region of the autumn sky with StarGlobe.

Quick Facts

Pisces covers 889 square degrees, ranking 14th in size. It contains one Messier object (M74). Its brightest star, Eta Piscium, shines at only magnitude 3.6. The constellation's right ascension ranges from about 22h 51m to 2h 06m, and its declination spans from about -7 to +34 degrees. The ecliptic runs through Pisces, and the vernal equinox currently lies within its borders.