Pisces is a zodiac constellation traditionally representing two fish connected by long cords. Although one of the larger constellations, it can be difficult to recognize because its stars are relatively faint, with even its brightest, Alpherg, shining at only magnitude 3.6. Visible from latitudes between approximately 90° north and 65° south, Pisces is best observed during fall in the Northern Hemisphere, preferably under dark, moonless skies.
Finding Pisces in the Night Sky
Start by locating the Great Square of Pegasus, a large four-star pattern prominent in the fall sky. This is one of the easiest landmarks for finding Pisces, which lies mainly below and to the east of the Square. Once you’ve found the Great Square, look below its southern side for the Circlet of Pisces, a small loop of faint stars marking the western fish. Most of its stars are around fourth or fifth magnitude, so dark skies away from city lights make it much easier to identify.
From the Circlet, a chain of faint stars extends toward Alrescha (Alpha Piscium), where the two cords connecting Pisces’s traditional fish meet. Together, these chains form a broad V-shaped pattern, with the second fish extending toward the stars east of the Great Square of Pegasus. Following this pattern is much easier than trying to distinguish the two fish depicted in traditional constellation artwork.
The Principal Stars of Pisces
The stars of Pisces vary considerably in distance and characteristics, with several helping to trace the constellation’s two fish and their connecting cords.
- Alpherg (Eta Piscium) is Pisces’s brightest star, shining at magnitude 3.6. An evolved yellow giant roughly 350 light-years away, it carries the Greek letter Eta rather than Alpha because Bayer star designations do not always follow a strict brightness ranking.
- Alrescha (Alpha Piscium) lies where the two cords connecting Pisces’s traditional fish meet. Its Arabic-derived name refers to “the cord,” and it is actually a multiple-star system located roughly 150 light-years away.
- Gamma Piscium shines at around magnitude 3.7 and is the brightest star in the Circlet, making it a useful landmark for identifying the western fish.
- Iota Piscium is another fourth-magnitude star that helps outline the Circlet. Located only about 45 light-years away, it is considerably closer than many of Pisces’s other prominent stars.
Van Maanen’s Star: Early Evidence of Another Planetary System
One of the most remarkable stars in Pisces is invisible to the naked eye. Van Maanen’s Star is a white dwarf just 14 light-years away, the dense remnant of a star that has exhausted its nuclear fuel and shed its outer layers.
In 1917, astronomers detected calcium in its atmosphere, something unusual because heavy elements should sink beneath a white dwarf’s visible surface. Astronomers now interpret this as evidence of rocky debris from a former planetary system, such as asteroids being broken apart and falling onto the white dwarf.
Remarkably, astronomers had unknowingly recorded evidence of planetary material beyond our Solar System as early as 1917, decades before the first exoplanets were confirmed. The significance of that observation was only recognized much later.
M74 Offers a Face-On View of a Spiral Galaxy
Pisces contains just one Messier object: M74, a grand-design spiral galaxy roughly 32 million light-years away. Seen almost face-on from Earth, its sweeping spiral arms contain young blue stars, glowing star-forming regions and dark lanes of dust. NASA estimates that M74 contains around 100 billion stars.
Despite its spectacular appearance in photographs, M74 is notoriously difficult to observe through a telescope. Its light is spread across a large area of sky, giving it low surface brightness. Through a small telescope, it appears as a faint, diffuse patch rather than the impressive spiral seen in images. NASA describes it as one of the most difficult Messier objects to observe.
Beyond M74, Pisces contains interacting galaxies and more distant galaxy systems, explored in our Deep-Sky Objects in Pisces guide.
Pisces in Ancient Mythology
Pisces has roots in ancient Mesopotamian astronomy, when the stars were associated with different figures, including a great Swallow and the goddess Anunitu. Some of the star patterns that eventually became the cords joining Pisces’s two fish were already present in these older figures.
Over time, the figures evolved. Images on ancient seals from Uruk depict a fish and a bird connected by a V-shaped ribbon, an intermediate form resembling the later depiction of two fish joined by cords. By classical antiquity, the constellation had taken on a form recognizable in modern star charts.
Greek mythology later associated the two fish with Aphrodite and Eros, who escaped the monster Typhon by transforming into fish or being carried to safety by them, depending on the version.
Why the First Point of Aries Is Actually in Pisces
The zodiac forms a circle around the sky, following the Sun’s apparent path through the stars. Astronomers needed a starting point for measuring positions along that path, so they adopted the March equinox, when the Sun crosses the celestial equator from south to north. This point defines zero degrees of ecliptic longitude.
More than 2,000 years ago, this point lay in the constellation Aries, giving it the name First Point of Aries. But Earth slowly wobbles on its axis in a roughly 26,000-year cycle known as precession, gradually shifting the equinox point against the background stars.
Today, the March equinox lies in Pisces, although its traditional name has remained unchanged. This is why Pisces is sometimes described as the first constellation of the zodiac—not because the zodiac has an official first constellation, but because Pisces now contains its traditional starting point.
