Look up at a clear night sky and the stars appear scattered across the darkness. For thousands of years, however, people have connected them into recognizable patterns, imagining hunters, animals, heroes, objects and mythical creatures stretched across the heavens.
Today, astronomers officially divide the entire sky into 88 constellations. This guide explains what those constellations really are, lets you explore all 88, and shows you how to start finding your way among them.
Explore all 88 constellations ↓ | New to constellations? Start here ↓
What Is a Constellation?
We usually think of a constellation as a recognizable pattern formed by stars in the night sky. That’s the traditional idea, but in modern astronomy a constellation means something more precise.
Astronomers divide the entire sky into 88 officially defined regions, rather like a map divided into territories. Every star, nebula and galaxy we see therefore belongs to one of those constellations, whether or not it forms part of the familiar star pattern.
Those patterns help us recognize the constellations, but they don’t define their official boundaries. Even the imaginary stick-figure lines commonly drawn between their stars aren’t official and can vary between star charts. The stars themselves aren’t necessarily close together in space either: they can lie at very different distances and only appear grouped together from our viewpoint on Earth.
Some familiar star patterns aren’t constellations at all. The Big Dipper, for example, is only part of the much larger constellation Ursa Major. Patterns like this are called asterisms: recognizable groups of stars that don’t form one of the 88 official constellations.
Explore All 88 Constellations
The International Astronomical Union (IAU) recognizes 88 constellations, covering every part of the sky. Use the complete alphabetical list below to explore them individually; each constellation name links to its dedicated AstronomyTrek guide, where you can learn more about its stars, location, history and other interesting features.
Not sure where to begin? Jump to our beginner’s guide below ↓
| Andromeda Chained Maiden | Lacerta Lizard |
| Antlia Air Pump | Leo Lion |
| Apus Bird of Paradise | Leo Minor Lesser Lion |
| Aquarius Water Bearer | Lepus Hare |
| Aquila Eagle | Libra Scales |
| Ara Altar | Lupus Wolf |
| Aries Ram | Lynx Lynx |
| Auriga Charioteer | Lyra Lyre |
| Boötes Herdsman | Mensa Table Mountain |
| Caelum Engraving Tool | Microscopium Microscope |
| Camelopardalis Giraffe | Monoceros Unicorn |
| Cancer Crab | Musca Fly |
| Canes Venatici Hunting Dogs | Norma Carpenter’s Square |
| Canis Major Great Dog | Octans Octant |
| Canis Minor Lesser Dog | Ophiuchus Serpent Bearer |
| Capricornus Sea Goat | Orion Hunter |
| Carina Keel | Pavo Peacock |
| Cassiopeia Seated Queen | Pegasus Winged Horse |
| Centaurus Centaur | Perseus Hero |
| Cepheus King | Phoenix Phoenix |
| Cetus Sea Monster | Pictor Painter’s Easel |
| Chamaeleon Chameleon | Pisces Fishes |
| Circinus Drawing Compass | Piscis Austrinus Southern Fish |
| Columba Dove | Puppis Stern |
| Coma Berenices Berenice’s Hair | Pyxis Mariner Compass |
| Corona Australis Southern Crown | Reticulum Reticle |
| Corona Borealis Northern Crown | Sagitta Arrow |
| Corvus Crow | Sagittarius Archer |
| Crater Cup | Scorpius Scorpion |
| Crux Southern Cross | Sculptor Sculptor |
| Cygnus Swan | Scutum Shield |
| Delphinus Dolphin | Serpens Serpent |
| Dorado Swordfish | Sextans Sextant |
| Draco Dragon | Taurus Bull |
| Equuleus Little Horse | Telescopium Telescope |
| Eridanus River | Triangulum Triangle |
| Fornax Furnace | Triangulum Australe Southern Triangle |
| Gemini Twins | Tucana Toucan |
| Grus Crane | Ursa Major Great Bear |
| Hercules Hercules | Ursa Minor Little Bear |
| Horologium Clock | Vela Sails |
| Hydra Female Water Snake | Virgo Maiden |
| Hydrus Male Water Snake | Volans Flying Fish |
| Indus Indian | Vulpecula Fox |
Why Are There 88 Constellations?
Why 88 rather than some other number? The answer is partly historical. People were identifying constellations thousands of years before modern astronomy, and many of the patterns familiar to us today have ancient origins. Around the second century AD, the Greek astronomer Claudius Ptolemy catalogued 48 constellations in his Almagest, representing much of the sky visible from the Mediterranean region.
More constellations were introduced as European explorers and astronomers mapped previously uncharted parts of the southern sky, but there was no universally agreed system of names and boundaries.
In 1922, the International Astronomical Union adopted the modern list of 88 constellations. Their official boundaries were subsequently defined and published by 1930, so that together the constellations divide the entire sky without gaps. Wherever you point a telescope, you are therefore looking into one of them.
New to Constellations? Start Here
Seeing a list of 88 constellations can make learning the night sky look much harder than it really is. The trick isn’t to memorize 88 names at once. Start by recognizing a few obvious shapes, then use them as landmarks to find your way around the surrounding sky.
Start With an Easy Pattern
For Northern Hemisphere observers, Orion is one of the easiest constellations to learn. It’s large, bright and distinctive, with four prominent stars forming a rough rectangle around the unmistakable line of three stars in Orion’s Belt. Once you recognize this shape, the Belt becomes a useful signpost to other parts of the winter sky.
Extend the line of Orion’s Belt in one direction and it leads toward Sirius, the brightest star in the night sky, in the constellation Canis Major. Extend it in the opposite direction and it points roughly toward Aldebaran, a bright reddish star in the constellation Taurus.
Another useful northern landmark is Ursa Major, a large constellation containing the seven bright stars that form the familiar Big Dipper asterism, which can also be used to find Polaris, the North Star.
In the Southern Hemisphere, Crux, the Southern Cross, provides a similarly distinctive starting point. Its compact cross shape is easy to recognize, while two nearby bright stars, Alpha and Beta Centauri, point toward it and can help you locate it.
The important thing isn’t which constellation you learn first. It’s the method: find one reliable landmark, learn what surrounds it, and gradually expand outward.
Which landmark makes the best starting point, however, depends on where—and when—you are looking.
Learn What’s Visible From Where You Live
You won’t be able to see all 88 constellations from one location, and the sky doesn’t stay the same throughout the year. What you can see depends mainly on your latitude, the season and the time of night.
Some constellations lie so far north or south that they never rise from certain parts of Earth, while others can be seen from large portions of both hemispheres. The constellations visible in the evening also change with the seasons. As Earth orbits the Sun, the nighttime side of our planet gradually faces different parts of space, bringing different constellations into view. Six months later, Earth is on the opposite side of its orbit and the nighttime sky faces roughly the opposite direction.
This is why Orion is a familiar sight on winter evenings in the Northern Hemisphere but appears during summer in the Southern Hemisphere. Some constellations are also circumpolar from particular latitudes, meaning they remain above the horizon throughout the year.
So the easiest constellation to learn is often simply one that’s prominent in your sky tonight.
Explore constellations by season →
Use Stories and Connections to Remember Them
Constellations don’t have to be learned as 88 unrelated names. Some occupy neighboring parts of the sky and are connected by the same traditional stories.
Perseus, Andromeda, Cassiopeia and Cepheus, for example, appear in the same broad region of the northern sky and are characters in the same Greek myth: Perseus rescues Andromeda, whose parents are Cassiopeia and Cepheus. Learning the story gives you a memorable way to connect several neighboring constellations rather than learning four unrelated names.
Once you recognize one constellation, learning its neighbors gradually turns that part of the sky into familiar territory. The names begin to connect with shapes, locations and stories, and over time what first looked like a scattering of stars becomes a map of recognizable landmarks.
Learn how to map the night sky using Orion →
Explore More of the Constellation Sky
Once you’ve started recognizing the constellations, there are several ways to explore them in more depth.
Constellations by Season
For Northern Hemisphere observers, our winter, spring, summer and autumn constellation guides highlight some of the most recognizable patterns visible during each season.
Zodiac Constellations
Our dedicated guide explores the familiar 12 zodiac constellations and explains why the Sun’s annual path through the sky actually carries it through a 13th constellation, Ophiuchus.
Explore the Zodiac constellations →
Asterisms
Some of the most recognizable patterns in the night sky aren’t official constellations at all. Asterisms such as the Big Dipper, Summer Triangle, Northern Cross and Teapot are easy-to-recognize patterns that can act as useful signposts when you’re learning your way around the night sky.
Interesting Constellation Facts
Which constellation is the largest or smallest? How do constellations appear to move across the sky, and how far back do some of their stories go? For more records, history and other surprising details, explore our separate collection of constellation facts.