Pisces: The Fishes

Pisces is easy to walk past. It is faint, spread out, and shares the sky with the far more obvious Great Square of Pegasus right next to it. But once you know what you are looking for, a specific star gives away the whole shape: a knot tying two fish together by a cord, marked by the star named for exactly that.

Two fish, one cord, one knot

Pisces's brightest star is Alpherg, Eta Piscium, a yellow giant at magnitude 3.62. Its Alpha star, Alrescha, is a binary at magnitude 3.82, dimmer than Alpherg despite the naming convention that would suggest otherwise. Alrescha's name means "the cord," and it marks the literal knot in the imagery: the point where two fish, tied together tail to tail, are joined. Pisces's best month is November, and the Great Square of Pegasus is the easiest landmark for finding it, since Pisces sits just below.

Two fish escaping a monster, in two different traditions

The Greek myth has the two fish as Aphrodite and her son Eros, who transformed into fish and tied themselves together with a cord to escape the monster Typhon. Alrescha, "the cord," marks the exact knot that keeps them joined even in flight.

A separate tradition reaches a similar image by a different route. Syrian sky lore links this same patch of stars to Atargatis, a goddess associated with sacred fish, a fish-and-water image from that region that fed into the later Greek story rather than the other way around. It is a genuinely interesting case of an image with real depth behind it, rather than a myth invented from nothing.

A ghost hiding among two faint fish

Pisces holds one standout deep-sky object, M74, a face-on spiral galaxy nicknamed the Phantom Galaxy for how difficult it is to spot, even though it is facing us directly. Its low surface brightness means it rewards a genuinely dark sky and a bit of patience far more than most galaxies do.

The fish in the sky and the sign in your chart parted ways long ago

Pisces the constellation is this specific pair of fish, tied by a cord, with fixed boundaries drawn on a star chart. Pisces the zodiac sign is a different kind of object entirely: a thirty-degree slice of the tropical zodiac, defined by the seasonal calendar rather than by where these particular stars actually sit. The two constellations and signs across the whole zodiac used to track each other far more closely than they do now, and precession, the slow drift of Earth's axis, is the reason they have separated. Our precession piece explains why that happens, and the astrological sign itself has its own page, separate from this constellation.

What this means for you tonight

If Pisces shows up in your chart, that is the tropical sign, and it will not be sitting in this literal spot in the sky when you go looking, so treat the two as related but distinct facts rather than one and the same. Go find the constellation anyway, in November: locate the Great Square of Pegasus first, since it is far easier to spot, then look just below and to the south for the fainter chain of stars that makes up the fish. Once you have Alpherg and Alrescha, notice that Alrescha, the Alpha star and the one that gives the whole figure its name, is actually dimmer than Alpherg — one more reminder that Greek letters were not assigned by strict rank. If your sky is dark enough, this is also a good constellation to practice patience in: the Phantom Galaxy earned its nickname honestly, and finding it is a small, real accomplishment. For more on how star naming and brightness relate, read how star brightness works, and for the basics of how any constellation's boundaries are actually defined, see what a constellation is.