99 Fun Facts About Constellations

How many constellations does the International Astronomical Union officially recognise?

By 1930 the whole sky had been carved into 88 tidy regions so that every star belongs to exactly one of them.

Which constellation is the largest of all, sprawling across roughly 1,303 square degrees of sky?

Hydra, the water snake, covers 1,303 square degrees and stretches more than 100 degrees across the sky, yet has only one reasonably bright star, Alphard, 'the solitary one'.

Which constellation is the smallest of all by area?

Crux, the Southern Cross, covers just 68 square degrees; the ancient Greeks could see its stars and counted them as part of a neighbouring figure, until precession carried them below Europe's horizon.

Which 2nd-century astronomer listed 48 constellations, 12 of them the zodiac, in his Almagest?

Ptolemy, working in Alexandria around AD 150, listed 48 constellations; later astronomers filled the gaps between his figures and mapped the far southern sky that never rose above his horizon.

Which ancient Greek constellation was later broken up into Carina, Puppis and Vela?

Argo Navis, the Argonauts' ship, grew so unwieldy that an 18th-century French astronomer divided it into Carina (the keel), Puppis (the stern) and Vela (the sails); its brightest star, Canopus, now belongs to Carina.

The French astronomer Lacaille named 14 southern constellations in the 1750s mostly after what?

Scientific instruments such as the air pump, the furnace, the microscope and the pendulum clock fill his corner of the sky, a tribute to the tools of the Enlightenment rather than to old legends.

Which Cape Town landmark did a French astronomer honour with a constellation after charting the southern sky beside it?

Table Mountain became the constellation Mensa, 'the table'; part of the Large Magellanic Cloud lies inside it, capping the stars much as the 'tablecloth' cloud caps the real mountain.

Whose 1603 atlas Uranometria, the first to cover the whole celestial sphere, introduced Greek-letter star labels?

Johann Bayer was an Augsburg lawyer, not a professional astronomer, yet the system from his 1603 Uranometria, lettering each constellation's stars roughly by brightness, is still in use four centuries later.

Navigators of which nationality charted the stars of 12 new southern constellations on a 1590s East Indies voyage?

Dutch navigators Pieter Keyser and Frederick de Houtman mapped the southern stars on that voyage; Keyser died before the fleet got home, but his notes gave the sky Tucana the toucan and Volans the flying fish.

In a name like 'Alpha Centauri', what grammatical case of the constellation's Latin name follows the Greek letter?

Genitive means Alpha Centauri is literally 'Alpha of the Centaur' and Alpha Tauri 'Alpha of the Bull'; Flamsteed numbers use the same possessive form.

Which 17th-century Gdańsk astronomer and brewer introduced Canes Venatici, Sextans and Leo Minor?

Johannes Hevelius, a Gdańsk brewer, charted ten new constellations, seven still in use, and kept measuring star positions by naked eye long after rivals such as Robert Hooke insisted on telescopic sights.

Scutum, the Shield, was named in honour of which monarch's victory at the 1683 Battle of Vienna?

John III Sobieski of Poland had helped the constellation's inventor rebuild his observatory after a fire in 1679, and the astronomer repaid him in 1684 with Scutum Sobiescianum, Sobieski's Shield.

Which faint constellation got its name because the astronomer who created it said only the sharp-eyed could see it?

Lynx covers more sky than Gemini, yet it has no star brighter than third magnitude, so its patch of the northern sky looks almost empty.

Which 'serpent-bearer' constellation does the Sun cross each year without being a zodiac sign?

Ophiuchus hosts the Sun for about 18 days from the end of November, yet astrology's twelve signs are equal 30-degree slices that ignore the real constellation boundaries.

The serpent-bearer constellation is identified with which Greek healer whose staff symbolises medicine?

Asclepius, son of Apollo, was said to have learned to raise the dead by watching one snake revive another with a herb; Zeus struck him down with a thunderbolt, then set him among the stars to appease Apollo.

Which constellation is uniquely split into two parts, Caput in the west and Cauda in the east?

Serpens is split into Serpens Caput, the head, and Serpens Cauda, the tail, because the man gripping the snake stands between them; the tail half holds the Eagle Nebula and its Pillars of Creation.

Which is the only zodiac sign represented by an inanimate object?

Libra, the scales, was once seen as the claws of neighbouring Scorpius; its two brightest stars keep Arabic names meaning 'southern claw' (Zubenelgenubi) and 'northern claw' (Zubeneschamali).

Into which constellation has the 'First Point of Aries' drifted due to precession?

The vernal equinox point has slid westward into Pisces, moving about one degree every 72 years; the name was fixed over 2,000 years ago when the equinox really lay in the Ram.

The Crab Nebula, remnant of a supernova seen from Earth in 1054, lies in which zodiac constellation?

The Crab Nebula (M1) lies near Zeta Tauri in Taurus, which also holds the Pleiades and the Hyades; Chinese records say the 1054 supernova was visible by day for about three weeks.

Which of the celestial Twins is actually brighter, though its sibling got the 'Alpha' designation in 1603?

Pollux outshines Castor by nearly half a magnitude; in the usual telling of the myth he was also the immortal twin, who asked Zeus to let him share that gift with his fallen brother.

Which red supergiant on Orion's shoulder faded sharply in the 'Great Dimming' of 2019–20?

Betelgeuse faded because it threw off a huge mass of its own gas, which cooled into a veil of dust and hid part of the star; it is expected to explode as a supernova within about 100,000 years.

Alnitak, Alnilam and Mintaka form which famous part of the hunter Orion?

Alnitak, Alnilam and Mintaka make up Orion's Belt; extend their line to the south-east and it points straight at Sirius, the brightest star in the night sky.

The Orion Nebula, one of the brightest nebulae in the sky, lies in which part of the hunter's figure?

The Orion Nebula (M42) is the middle 'star' of Orion's Sword, hanging below the Belt; at around 1,300 light-years it is the closest region of massive star formation to Earth.

In Greek myth, which creature killed Orion, which is why its constellation never shares the sky with the hunter?

A scorpion, sent in one telling by the Earth after Orion boasted he could kill any wild beast, and in another by Artemis; the two now sit on opposite sides of the sky, so one rises as the other sets.

Which red supergiant marks the heart of Scorpius?

Antares, often translated as 'rival of Mars', is named for its strong reddish colour, which resembles the planet's; it is a red supergiant about 550 light-years away.

Sirius, the brightest star in the night sky, belongs to which constellation?

Sirius, the 'Dog Star', lies just 8.6 light-years away in Canis Major, the Greater Dog, pictured chasing Lepus the Hare at the heels of Orion.

Which asterism joins Sirius, Procyon, Capella, Aldebaran and Rigel around Betelgeuse?

The Winter Hexagon needs a sixth corner, Pollux, to close the ring; the smaller Winter Triangle sits inside it, sharing Sirius and Procyon and using Betelgeuse as its third point.

Polaris, the North Star, is the brightest star of which northern constellation?

Ursa Minor's Polaris sits at the tip of the Little Dipper's handle, and despite its fame it is not even among the 40 brightest stars in the sky.

Which star in Draco, the Dragon, was the pole star nearly 5,000 years ago, when Egypt's pyramids were being built?

Thuban, Alpha Draconis, sat almost exactly at the pole in the pyramid age; Earth's axis wobbles in a 26,000-year cycle, so the honour moves on, and Vega takes the job in about 12,000 years.

The Big Dipper is not a constellation at all but an asterism inside which one?

Ursa Major, the Great Bear, uses the Dipper as its rump and tail; unusually for a star pattern, five of the seven stars really are neighbours, drifting through space together as one group.

In the UK, the seven-star pattern Americans call the Big Dipper is usually known as what?

The Plough is the usual British name; the Romans saw the same seven stars as plough oxen, septentriones, a name that came to mean 'the north' itself.

Which two stars at the edge of the Big Dipper's bowl point the way to the North Star?

Dubhe and Merak, the Pointers, lie at the bowl's outer edge; follow the line from Merak through Dubhe for about five times their separation and you land almost exactly on Polaris.

Which Big Dipper handle pair, the Arabs' 'horse and rider', served as a traditional eyesight test?

Mizar and Alcor, the 'horse and rider' at the bend of the handle, are 12 arcminutes apart; Alcor is bright enough to see, but separating it from Mizar with the naked eye was the test.

In Ovid's telling of the myth, which goddess turned Callisto into the bear that became the Great Bear?

Hera, the Juno of Ovid's poem, struck again after Zeus set Callisto and her son Arcas among the stars: she persuaded the sea gods never to let her rival bathe below the horizon.

Which W-shaped northern constellation is named for a vain queen who boasted of her beauty?

Cassiopeia was set in the sky to spend half of every night hanging upside down as punishment, and Tycho Brahe's supernova of 1572 blazed among her stars.

Which constellation is named for the slayer of Medusa, who also rescued a chained princess?

Perseus holds Algol, the 'Demon Star' marking Medusa's severed head, which seems to wink every 2.9 days as its dimmer companion passes in front of the brighter star.

Messier 31, the nearest major galaxy to the Milky Way, is named after and lies in which constellation?

Andromeda's great galaxy is one of the most distant things you can see with the naked eye: the light reaching you tonight left it about 2.5 million years ago.

Vega is the brightest star of which small northern constellation?

Lyra, Orpheus's lyre, also holds the Ring Nebula (M57), one of the best-known planetary nebulae; Vega was the pole star around 12,000 BC and will be again around AD 14,000.

The centre of the Milky Way lies in which constellation, whose brightest stars form the 'Teapot'?

Sagittarius gives its name to Sagittarius A*, the supermassive black hole at the galaxy's core, and the unexplained 1977 'Wow!' radio signal also came from this constellation.

Alpha and Beta of which constellation are the 'southern pointers' to the true Southern Cross?

Centaurus holds Alpha Centauri, the closest star system to the Sun; its two pointers matter because the nearby False Cross, a larger and dimmer look-alike, has no such pair beside it.

Which country's flag depicts the sky on the morning its republic was proclaimed in 1889?

Brazil's flag shows the sky over Rio de Janeiro on 15 November 1889, one star for each state and the Federal District, drawn as if seen from outside the heavens, so the constellations appear mirror-reversed.

Which of these pairs of Pacific nations both show the Southern Cross on their flags, as Australia does?

Papua New Guinea and Samoa both fly the Southern Cross; Papua New Guinea's version, five white stars beside a bird of paradise, was designed in 1971 by a 15-year-old schoolgirl, Susan Karike.

Which constellation contains the south celestial pole and is named after a navigational instrument?

Octans, the octant, holds the south celestial pole; its 'pole star' Sigma Octantis is a feeble magnitude 5.4, which is why southern navigators steer by the Southern Cross instead.

The Aboriginal Australian 'Emu in the Sky' is traced not from stars but from what?

Dark dust clouds of the Milky Way form it: the emu's head is the Coalsack Nebula beside the Southern Cross, and the body and legs trail along the Great Rift to Scorpius.

China's 28 lunar mansions are shared by a dragon, bird, tiger and which creature?

Tortoise: the Black Tortoise, shown with a snake coiled around it, guards the north; each creature rules seven mansions, and the Moon lodges in a new one roughly every night.

Which constellation represents the hair an Egyptian queen sacrificed for her husband's safe return?

Coma Berenices recalls Queen Berenice II: when the hair she had offered vanished from the temple overnight, the court astronomer Conon of Samos declared it had been set among the stars.

Which zodiac constellation contains the Sickle, a backwards question mark of stars with Regulus at its foot?

Leo is the Nemean lion of Greek myth: arrows bounced off its hide, so Hercules had to strangle it with his bare arms.

Vega, Deneb and Altair, each the brightest star of its constellation, form which large asterism?

The Summer Triangle links very unequal stars: Vega and Altair are near neighbours of the Sun, while Deneb lies dozens of times farther away and only looks their equal because it is vastly more luminous.

Which astronomer detected the first pulsar in Vulpecula in 1967?

Jocelyn Bell Burnell found it as a graduate student: radio blips arriving every 1.3 seconds, so regular that her team nicknamed the signal LGM-1, for 'little green men'.

Which Japanese carmaker takes both its name and its six-star badge from the Pleiades star cluster?

Subaru is the Japanese name for the cluster. The badge shows only six stars because tradition holds that one of the Seven Sisters is invisible.

Which US state's flag shows the Big Dipper and the North Star in gold on a dark blue field?

Alaska picked a design by schoolboy Benny Benson from roughly 700 entries in a 1927 children's contest, 32 years before it became a state.

The first black hole ever photographed sits in the giant galaxy M87, which lies in which constellation?

Virgo is home to M87, a giant galaxy of several trillion stars. The Event Horizon Telescope's picture of its black hole was released on 10 April 2019.

The oldest known depiction of the classical constellations survives on a Roman marble statue of which Titan?

Atlas kneels beneath the star globe in a Roman statue now in Naples, itself probably a copy of an older Greek work.

Which star on Orion's shoulder takes its name from the Latin for 'female warrior'?

Bellatrix is the third-brightest star in Orion. Harry Potter's Bellatrix Lestrange follows the Black family habit of taking names from the sky.

The curve of the Big Dipper's handle points to which red giant, the brightest star in the northern half of the sky?

Arcturus switched on the 1933 Chicago World's Fair. Its light was used to trigger the opening because it was thought to have left the star during the city's 1893 fair.

Musca is the only insect among the official constellations; which insect does this small southern figure depict?

A fly is what Dutch navigators saw there in the 1590s, though for the next two centuries star maps labelled the same stars Apis, the Bee.

In Greek myth, the flying ram behind the constellation Aries later yielded which famous treasure?

The Golden Fleece came from the ram that flew Phrixus to safety in Colchis. He sacrificed the animal there, and it was set among the stars.

Deneb marks the tail and the Northern Cross forms the body of which constellation of the northern summer sky?

Cygnus, the Swan, also holds Cygnus X-1, the first object widely accepted to be a black hole.

Which 'Demon Star' fades for about ten hours every 2.86 days as a dimmer companion star passes in front of it?

Algol's winking was noted in 1667, but it took amateur astronomer John Goodricke, more than a century later, to spot its clockwork rhythm and propose a cause.

Altair is the brightest star of which constellation, said to be the bird that carried the thunderbolts of Zeus?

Aquila is Latin for eagle. A rival telling makes it the bird that Zeus sent to torment the chained Prometheus.

A great square of four stars marks which constellation, where a planet was first found orbiting a Sun-like star?

Pegasus holds the star 51 Pegasi, whose planet is a hot Jupiter that completes an orbit every four days.

The Beehive Cluster, one of the first sights Galileo turned a telescope on, lies in which faint zodiac constellation?

Cancer is the dimmest constellation of the zodiac, yet its Beehive spans about three times the width of the full Moon. Galileo picked out some forty stars in it.

Which constellation is identified with Ganymede, the Trojan prince carried to Olympus to pour wine for the gods?

Aquarius, the Water Bearer, stands for the son of King Tros in this telling, a beautiful youth snatched away by an eagle at the command of Zeus.

Mira, a pulsating star that fades from view and returns about every 332 days, lies in which constellation?

Cetus holds Mira, whose name is Latin for 'wonderful'. By 1638 an observer had worked out that the star vanishes and returns on a cycle of about eleven months.

Which star, the second-brightest in the night sky, has guided spacecraft since Mariner 4 locked onto it in 1964?

Canopus was the first star ever used to steer a spacecraft, and many later probes carried a dedicated camera known as a Canopus star tracker.

Which bright autumn star, circled by rings of debris, takes its name from the mouth of the Southern Fish?

Fomalhaut once seemed to have a planet photographed beside it, but later analysis showed the speck was an expanding region of debris from a massive collision.

Corona Borealis, the Northern Crown, represents the wedding crown of which Cretan princess abandoned by Theseus?

Ariadne wore the crown at her marriage to the god Dionysus in the usual telling, and he then placed it in the heavens to commemorate their wedding.

Which long constellation, drawn as a river, winds far to the south and ends at the bright star Achernar?

Eridanus ends at a star that spins so fast it bulges: Achernar's equator is about 35% wider than the distance between its poles.

Most of the Large Magellanic Cloud lies in which southern constellation, named after the mahi-mahi or dolphinfish?

Dorado is the Spanish name for the fish, after its colour. The Rudolphine Tables of 1627 gave the same stars a rival name, Xiphias.

The Hubble Ultra-Deep Field, a tiny patch of sky holding some 10,000 galaxies, lies in which constellation?

Fornax began life as the 'Chemical Furnace', first drawn with an alembic and receiver by a French astronomer who charted the southern stars from the Cape of Good Hope.

Which Dutch mapmaker and church minister trained a ship's pilot to chart southern stars, then drew them on a globe?

Petrus Plancius briefed the pilot Pieter Keyser before a 1595 voyage to the East Indies. Keyser died on the voyage, but his catalogue of 135 stars made it home.

MUL.APIN, a compendium of 66 stars and constellations likely compiled around 1000 BCE, comes from which civilisation?

Babylonian sky-watchers also noted when each star rose, set and culminated, details that let scholars map out the basic structure of their sky today.

In Chinese astronomy, which of the Four Symbols guards the southern sky and stands for summer and fire?

The Vermilion Bird resembles a pheasant wrapped in flames. It is often mistaken for the fenghuang, the legendary ruler of birds, but the two are different creatures.

Which January meteor shower is named after a constellation that no longer exists on official star charts?

Quadrantids take their name from Quadrans Muralis, the Mural Quadrant, a figure created in 1795 from parts of Boötes and Draco and later dropped.

Star names pairing a number with a constellation honour which English compiler of the first major telescopic catalogue?

John Flamsteed never approved the scheme. It first appeared in a 1712 edition of his catalogue that Edmond Halley and Isaac Newton published without his consent.

Which animal does the constellation Lepus represent, crouching just south of Orion as if chased by the hunter?

A hare, though no particular one: unlike most ancient constellations, Lepus does not represent any specific figure in Greek mythology.

In Greek myth, which god flung the crow Corvus into the sky for lying about why it was late fetching water?

Apollo saw through the excuse, since the bird had stopped to eat figs. He set a cup beside it in the stars, forever just out of reach, so it would always be thirsty.

The small southern constellation Columba was first named after a bird linked to which biblical figure?

Noah's dove kept its famous prop in the sky: a Dutch star catalogue of 1603 listed the figure as the dove with the olive branch.

Camelopardalis, a large but faint northern constellation, is named from the Greek 'camel-leopard' for which animal?

A giraffe earned the Greek name because it has a long neck like a camel and spots like a leopard.

Which mythical beast does Monoceros represent, a faint constellation on the celestial equator just east of Orion?

Unicorn is what the Greek name means, and the faint figure hides the Rosette Nebula, a glowing nebula more than 100 light-years across.

In Hawaii, the hook-shaped constellation Scorpius is seen as the great fishhook of which hero of Polynesian legend?

Māui's hook even has a name of its own, Manaiakalani, and Hawaiians call the whole star pattern Ka Makau Nui o Māui, the Big Fishhook of Māui.

Which Japanese star festival celebrates the once-a-year meeting of two lovers represented by the stars Vega and Altair?

Tanabata means 'Evening of the Seventh': the pair may meet only on the seventh day of the seventh lunar month, when people write wishes on strips of paper.

Ancient Egyptians saw the stars of Orion as Sah, a figure identified with which god of the afterlife?

Osiris and his wife share the sky: Sirius, which rises just after Orion, was the goddess Sopdet, and she in turn was merged with Isis.

Most accepted star names in Western astronomy, including Deneb, Altair and Achernar, come from which language?

Arabic names reached Europe through translation: Ptolemy's star book was put into Arabic in the 8th and 9th centuries, then into Latin in the 12th.

Which German Renaissance artist produced the woodblocks for the first printed star charts in the West in 1515?

Albrecht Dürer made the charts in Nuremberg as a set of woodcut portraits of the constellation figures, the oldest printed star chart in Europe.

Julius Schiller's 1627 Christian star maps replaced the zodiac constellations with which group of biblical figures?

The apostles took over the zodiac, while New Testament figures replaced the northern constellations and Old Testament figures the southern ones.

The southern constellation Ara depicts which object, where the Greek gods formed an alliance before fighting the Titans?

An altar: star maps usually draw it as a compact classical altar with its smoke rising southward.

Which Greek astronomer discovered precession after finding the star Spica had shifted two degrees from older records?

Hipparchus compared his measurements with those of his predecessors Timocharis and Aristillus. He also compiled the first known comprehensive star catalogue in the western world.

Capricornus, the sea-goat, is sometimes identified with which Greek god, who grew a fish's tail to escape Typhon?

Pan, the god with a goat's horns and legs, saved himself by diving into a river, which is why the figure is half goat and half fish.

French astronomer Jérôme Lalande added which household pet to the sky in 1799 as a short-lived constellation?

A cat was overdue, felt Lalande, a cat lover who was sorry that none yet sat among the constellations even though the sky already held two lions.

Unlike most star patterns, five of the Big Dipper's seven stars are truly related; what do they share?

A common motion through space marks them as the core of the nearest moving group to Earth, about 80 light-years away and thought to share one origin.

Which Bronze Age artefact, unearthed in Germany in 1999, shows a cluster of seven stars usually read as the Pleiades?

The Nebra sky disc carries the oldest concrete depiction of astronomical phenomena known anywhere, and it was found by two men treasure-hunting with a metal detector.

Which galaxy in Canes Venatici was the first seen to have spiral structure, through Lord Rosse's 72-inch telescope?

The Whirlpool revealed its arms at Birr Castle in Ireland, at a time when such objects were still counted among the nebulae.

Which painter set the seven stars of the Big Dipper above the river Rhône in an 1888 night view of Arles?

Vincent van Gogh took a liberty with the sky: from the riverbank view he painted, those seven stars would not have been visible in that direction.

The Dendera zodiac, an Egyptian temple ceiling carved with constellation figures, is now displayed in which museum?

The Louvre shows the carved ceiling, which was removed from the Hathor temple at Dendera and moved to Paris in 1821, where it first hung in the Royal Library.

Which southern star flared in a 19th-century 'Great Eruption' to become, briefly, the second-brightest in the night sky?

Eta Carinae outshone Rigel as the outburst built and peaked in March 1843, then faded below naked-eye visibility after 1856. The debris now forms the Homunculus Nebula.

Which northern constellation, named for a mythical king of Aethiopia, gave its name to a key class of variable stars?

Cepheus holds Delta Cephei, the yellow supergiant that is the prototype of the Cepheid variables, pulsating stars astronomers use to measure cosmic distances.

Which star in Gemini looks single to the naked eye but is really a system of six stars arranged in three pairs?

Castor's three visible stars are each a tight pair of their own, so close together that the partners show up only in the stars' spectra.

Horologium, a faint southern constellation charted in the 1750s, depicts which timekeeping device with a seconds hand?

A pendulum clock joined the sky in 1756, described in French as a clock with pendulum and seconds hand by an astronomer who had just catalogued almost 10,000 southern stars.