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Proficiency Step #5---Constellations
This proficiency step will address the constellations and asterisms that have made the night sky both more
familiar and somewhat confusing. As in the previous step, we will discuss the history and lore of the
constellations as a whole—as well as a few of the more “recognized” individual constellations. There are 88
official constellations—too many to cover in great detail here. This proficiency step will serve as a “door
opener” to the night sky. It is hoped that interested people will take advantage of the many resources available
on the subject to become familiar with at least a dozen of the many interesting constellations. In fact,
proficiency in the subject of constellations and asterisms will require at least a basic knowledge of 12
constellations. The choice of which 12 constellations one must learn is entirely up to each individual.
The 88 modern Constellations
Andromeda • Antlia • Apus • Aquarius • Aquila • Ara • Aries • Auriga • Boötes • Caelum •
Camelopardalis • Cancer • Canes Venatici • Canis Major • Canis Minor • Capricornus • Carina •
Cassiopeia • Centaurus • Cepheus • Cetus • Chamaeleon • Circinus • Columba • Coma Berenices •
Corona Australis • Corona Borealis • Corvus • Crater • Crux • Cygnus • Delphinus • Dorado • Draco •
Equuleus • Eridanus • Fornax • Gemini • Grus • Hercules • Horologium • Hydra • Hydrus • Indus •
Lacerta • Leo • Leo Minor • Lepus • Libra • Lupus • Lynx • Lyra • Mensa • Microscopium • Monoceros •
Musca • Norma • Octans • Ophiuchus • Orion • Pavo • Pegasus • Perseus • Phoenix • Pictor • Pisces •
Piscis Austrinus • Puppis • Pyxis • Reticulum • Sagitta • Sagittarius • Scorpius • Sculptor • Scutum •
Serpens • Sextans • Taurus • Telescopium • Triangulum • Triangulum Australe • Tucana • Ursa Major •
Ursa Minor • Vela • Virgo • Volans • Vulpecula
Any discussion of astronomical objects necessarily must include a definition of the “celestial sphere”. Imagine
that a small marble was placed in the exact center of a basketball. If we call the marble “Earth” and the inside
of the basketball—as seen from the marble—the celestial sphere, we can imagine all of the stars and visible
objects in space as being “projected” onto the inside of the basketball. In reality every object in space is a
different distance from the earth, but for the purposes of “remembering” and locating them all, it is handy to
imagine them on an imagined plane around the earth. We can then divide this inside view of the sphere into
sectors for the purpose of locating objects.
What is a constellation, anyway? The International Astronomical Union divides the entire sky into 88 sections
of varying size and shape—and which correspond to particular groupings of stars that represent certain
shapes. Some well-known constellations contain instantly recognizable patterns of stars—while others have
patterns that are less than obvious--and in some cases quite dim. Most of the 44 northern constellations are
based on Greek traditions and are named after characters in Greek mythology. The constellation boundaries
were drawn up by Eugene Delporte in 1930—and to this day are used to designate the location of objects on
the celestial sphere. It is important to understand that the constellation is not the pattern defined by a group of
stars, but rather, the section of the sky (established by Delporte) that contains the pattern—although many
people refer to the patterns, themselves, as constellations.
What is an asterism? Asterisms are simply groupings of stars that form recognizable shapes—but that are not
representative of the constellation area, though they may (or may not) be part of a constellation figure. The
best example of this is the Big Dipper which is instantly recognizable as a dipper, but is actually the hind
quarters of Ursa Major (the big bear).
The summer triangle is an easily found asterism in the summer sky and is made up of three of the brightest
stars in the sky—each of which is actually in three separate constellation areas (Vega in Lyra, Deneb in
Cygnus, and Altair in Aquilla). The Coathanger asterism (officially called Brocchi’s cluster) is very small and
not at all noticeable with the naked eye—but easily viewed through binoculars. It is located about 1/3 of the
way from Altair to Vega in the summer triangle in the constellation Vulpecula. There are many other asterisms
in the northern hemisphere—and one can also envision and create one’s own asterism since they are not
officially recognized landmarks in the sky. They can, however, be quite helpful in learning to locate objects in
what could otherwise be a real confusing mess of stars. The ability to find at least three asterisms should be
considered part of becoming “proficient” in this proficiency step.
A few other asterisms: The “teapot” in Sagittarius, the “belt” of Orion, the “fishhook” of Scorpius, the “great
square” of Pegasus, the “seven sisters”, and the “W” of Cassiopeia.
We tend to think of constellations as a group of related stars that form a pattern, when in fact, most of the
constellations consist of stars that are not related—that is, they are varying distances from Earth and their
relative positions are simply a coincidence. It might be convenient to note here that the science of astronomy
has existed for many centuries—much longer than the invention of telescopes. Ancient peoples found that
dividing up the sky into “sectors” made things more manageable and easier to remember. The earliest
references to the constellations were from the Middle-eastern Sky Myths of the 8th century BC, but the most
complete early references can be found in the writings of the ancient Greek astronomer Eratosthanes and the
Roman writer Hyginus. They were adapted to Greek culture from prior Sumerian and Babylonian cultures.
Many other cultures had their own versions of constellations, including the Chinese, which had an elaborate
and well-established set of “different” constellations. Many of the stars have Arabic names—a testament to the
advanced astronomical “science” practiced by middle-eastern “astronomers” of centuries past.
This proficiency step will deal primarily with constellations of the northern hemisphere since it is impossible to
view many of the southern constellations from our Wisconsin location. Information about the southern
constellations is abundant on the internet and in all public libraries.
Most of the currently recognized northern constellations are variations of “star groupings” that were established
by the ancient Greeks. Although the groupings have changed over the centuries with the influences of various
cultures and prominent astronomers, the basic shapes and the lore accompanying the shapes has survived the
ages and to this day are used to remember where things are in the night sky. The stories are many and
varied—and while they are not required to remember the location of celestial objects, they can make the
pursuit of astronomy more interesting and fun. The basis for most of the stories are from Greek Mythology.
The Zodiac:
Imagine, for a moment, that we are on that marble (the Earth) inside the basketball (the celestial sphere). The
apparent path that the sun takes as the earth turns is called the Ecliptic. This is actually the path that the Earth
takes as it orbits the sun, but from our point of view on Earth it appears that the sun is moving across the sky.
The line it traces on the inside of the basketball as it goes all the way around the marble is the ecliptic. As it
happens, there are 13 constellations that are along this line. As in many things in life, someone decided that
one of them doesn’t count, but the other 12 comprise the constellations of the Zodiac. It might be a good idea
at this point to describe the difference between Astronomy and Astrology. Astronomy is the study of the
universe and everything in it (often generalized to the study of the night sky). Astrology is a “science” devoted
to the belief that certain constellations along the ecliptic have an affect on the lives of humans. In astronomical
circles, the zodiac is simply 12 (or 13) constellations that happen to lie along the line of the ecliptic. The 12
zodiacal constellations are: Aries, the ram; Cancer, the crab; Capricorn, the goat; Gemini, the twins; Leo, the
lion; Libra, the scales; Pisces, the fish; Sagittarius, the archer; Scorpius, the scorpion; Taurus, the bull; and
Virgo, the virgin.
General Constellation Lore:
Most ancient cultures saw pictures in the stars of the night sky. The earliest known efforts to catalog the stars
date to cuneiform texts and artifacts dating back roughly 6000 years. These remnants, found in the valley of
the Euphrates River, suggest that the ancients observing the heavens saw the lion, the bull, and the scorpion
in the stars. The constellations as we know them today are undoubtedly very different from those first few--our
night sky is a compendium of images from a number of different societies, both ancient and modern. By far,
though, we owe the greatest debt to the mythology of the ancient Greeks and Romans.
In Homer’s The Iliad, he describes the making of Achilles’ shield which had pictures of “the earth, and sky, and
sea, the weariless sun and the moon waxing full, and all the constellations that crown the heavens, Pleiades
and Hyades, the mighty Orion and the Bear, which men also call by the name of Wain: she wheels round in the
same place and watches for Orion, and is the only one not to bathe in Ocean.” (Iliad XVIII 486-490) At the time
of Homer, however, most of the constellations were not associated with any particular myth, hero, or god. They
were instead known simply as the objects or animals which they represented--the Lyre, for instance, or the
Ram. By the 5th century B.C., though, most of the constellations had come to be associated with myths, and
the Catasterismi of Eratosthenes completed the mythologization of the stars.
Despite the many mentions of the stars in Greek and early Roman texts, by far the most thorough star catalog
from ancient times belongs to the Roman Ptolemy of Alexandria, who grouped 1022 stars into 48
constellations during the 2nd century A.D. Although Ptolemy's Almagest does not include the constellations
which may only be seen from the southern hemisphere, it forms the basis for the modern list of 88
constellations officially designated by the International Astronomical Union. The influence of both the Greek
and Roman cultures may be plainly seen; the myths behind the constellations date back to ancient Greece, but
we use their Latin names. Mythology, of course, influenced the naming of many objects in the night sky, not
just the constellations. The planets all bear names from Roman mythology.
A Few Notable Constellations:
One of the oldest constellations, Ursa Major (ER-suh MAY-jer), The Great Bear
is also one of the best known. In particular are the seven stars which make up
what is commonly known as the Big Dipper or the Plough. In Cherokee legend,
the handle of the Big Dipper represents a team of hunters pursuing the bear.
The Iroquois of Canada and the Micmac's of Nova Scotia believe that each
spring the hunt begins when the bear leaves Corona Borealis, its den. Hunted
by seven warriors, the bear isn't killed until autumn when it disappears from the
sky. A new bear then emerges from Corona Borealis and the hunt begins
again. The early Britons interpreted the Big Dipper as King Arthur's chariot. The
Romans viewed it as a team of seven oxen, harnessed to the pole and driven by Arcturus. In Greek legend,
Zeus and Callisto, a mortal, had a son called Arcas. Hera, Zeus's jealous wife turned Callisto into a bear. One
day, while Callisto's son was out hunting he almost killed his mother. Rescued by Zeus, Callisto was placed in
the heavens with her son, whom Zeus also transformed into a bear. Callisto is Ursa Major and Arcas is Ursa
Ursa Major is full of unique celestial objects. The two outer edge stars that make up the "bowl" of the dipper
are Merak, the top one, and Dubhe. Connect a line between the two, and extend it north a distance about five
times the distance between them. It will connect with the North Star, Polaris. If you extend the handle of the
dipper with a line, it will lead to the star, Arcturus, in the constellation, Bootes. In one Greek myth, the star
represented the guardian, Arcturus, who kept the bears from straying from their path. Above the head of the
bear are two galaxies, M81 and M82. Both are 12 million light years away, but M81 is one of the brightest
galaxies in the sky. Finally, the Owl Nebula is located to the lower left of Dubhe. It is so named because some
photographs reveal what looks like a pair of eyes.
Most of the constellation is circumpolar, which means it can be viewed all year long. However, parts of the legs
will disappear from the sky in the fall and reappear in the winter.
Brightest Stars
NGC 3031 (M81)
NGC 3034 (M82)
NGC 3077
NGC 3079
NGC 3184
NGC 3198
Tanian Australis
NGC 3310
NGC 3556 (M108)
NGC 3992 (M109)
NGC 5457 (M101)
NGC 5475
NGC 3587 (M97--Owl Nebula)
Winnecke4 (M40—Double Star)
Orion (oh-RYE-un), the Hunter has been recognized for thousands of years. The
Chaldeans knew this group of stars as Tammuz, named after the month in which the
stars that make Orion's 'belt' become visible before sunrise. The Syrians called it Al
Jabbar, the Giant. The Egyptians called it Sahu, the soul of Osiris. In Greek
mythology, Orion was a giant and a great hunter. One legend tells how Artemis, the
goddess of the Moon and of the hunt, fell in love with Orion. Her twin brother, Apollo,
saw Orion swimming far out to sea. He challenged his sister to hit the faint dot among
the waves. Artemis shot an arrow, hitting and killing Orion. Inconsolable, she placed
his body in the heavens together with his hunting dogs. With the three stars that
make Orion's belt, Rigel and Betelgeuse make this one of the most attractive
constellations in the Northern Hemisphere from December to April.
For most observers Orion is the most impressive constellation of the sky. With its large number of bright stars
and the distinct group given by the three belt stars it is easy to find in the winter sky. Orion offers a wealth of
interesting and famous objects like the great Orion Nebula M 42/43 and the Horsehead Nebula (at IC 434).
The brightest star is Rigel (Beta Orionis), visible in the lower right. Against the convention, that greek letters
are given in order of intensity, the second bright star Betelgeuse is named Alpha Orionis (Orions left
Brightest Star
Open Clusters
NGC 1981
NGC 1976 (M42)
NGC 2175
NGC 1982
NGC 2068
IC 434
Cassiopeia (kass-ee-oh-PEE-uh) was the mother of Andromeda and the wife
of Cepheus, the Ethiopian King of Joppa. The Romans believed this striking
W-shaped constellation was Cassiopeia, chained to her throne as a
punishment for her vain boastfulness.
Cassiopeia is an easily-seen constellation that is in the far northern sky. It
circles the pole star (Polaris) throughout the year and also straddles the Milky
Way. The five major stars of Cassiopeia (also known as "The Lady of the Chair") are shaped like a "W" (or an
"M," depending on your orientation). All of the stars in Cassiopeia are all less than second magnitude
brightness. The brightest star in Cassiopeia is Schedar (alpha CAS), which is a multiple star that is pale rose in
color and varies in magnitude from 2.2 to 2.8 magnitudes. The second-brightest, called Caph (beta CAS), is a
white star of magnitude 2.4. Cassiopeia contains two open clusters, M52 (magnitude 7.3) and M103
(magnitude 7.4). The strongest radio source, Cassiopeia A, emanates from Cassiopeia; it is the remnant of a
supernova which ocurred about A.D. 1660, and is 10,000 light years from us.
Brightest Stars
Open Clusters
NGC 7654 (M52)
NGC 7635
NGC 7789
NGC 281
NGC 129
NGC 457
IC 1805
NGC 581 (M103)
NGC 1027
NGC 654
NGC 659
NGC 663
The Swan is one of the more obvious constellations in the summer skies. Because of
its shape it is sometimes called the Northern Cross. Cygnus (SIG-nus) is the northern
hemisphere's answer to the Crux. Cygnus straddles the northern Milky Way. One
story claims that Cygnus is Orpheus, the hero of Thrace who sang and played his lyre
so beautifully that wild animals and even trees would come and hear him play. It is
said that Orpheus was transported to the skies as a swan so that he could be near
his lyre.
Cygnus is sometimes called the Northern Cross. Deneb, visible as the tail of the
swan, is the brightest star of Cygnus with 1.26 mag. Together Deneb and Vega (in
Lyra) form the famous summer triangle with the star Altair in the more southern
constellation Aquila. A number of galactic deep sky objects reside in Cygnus, most striking of which is the so
called North America Nebula near the intersection of the “cross.”
Brightest Stars
Open Clusters
Planetary Nebula
NGC 6811
NGC 6826
NGC 6888
NGC 6819
NGC 6960
NGC 6834
IC 5067/70
NGC 6866
NGC 6992/5
NGC 6871
NGC 7000
NGC 6910
IC 5146
NGC 6913 M29)
NGC 6939
NGC 7092 (M39)
This is the fifth largest constellation, although it is not the most obvious. One of the most
famous of all of the classical heroes, Hercules (HER-kyu-leez) was incredibly strong and
was the half mortal son of Zeus. He was named after the greatest Greek goddess, Hera.
Hercules means 'glory (or honour) of Hera,' and he became a favorite with the gods. Apollo
made his bow and arrows, Athene gave him a magnificent robe, Hermes provided him with
a sword and Castor (the greatest warrior), taught him how to use it. Hephaestus, the
smithy of the gods, made a golden breastplate for Hercules. Armed and protected,
Hercules paraded through Greek mythology performing eight heroic acts and twelve
labors. At the end of his life, as a reward for his bravery, Jupiter made him one of the gods,
placing him in the sky.
Hercules’ appearence is quite faint, but the central trapeze is not so hard to find. In Hercules is the brightest
Globular Star Cluster of the northern hemisphere: M13. With a visual magnitude of 5.7 it can be seen by naked
eye as a very faint object. A small amateur telescope will resolve individual stars in M13. The brightest star
Alpha Herculis (3.1 mag) is Hercules’ left foot.
Brightest Star
Globular Cluster
NGC 6341 (M92)
NGC 6205 (M13)
The Little Bear, also known as the Little Dipper, Ursa Minor (ER-suh MY-ner) looks
like a spoon, or dipper, with the handle bent back. This collection of stars was
recognised by the Greek astronomer, Thales in 600BC. According to Greek legend,
Ursa Minor is Arcas, son of beautiful Callisto (Ursa Major, The Great Bear). Placed in
the sky by Zeus, Ursa Minor and Ursa Major follow each other endlessly around the north celestial pole.
This constellation is famous not only for being a “partner” to the ubiquitous “Big Dipper,” but it also has the
honor of containing the conspicuous pole star, Polaris. The dipper, itself, is not particularly bright or important,
but Polaris happens to approximately line up with the polar axis of the earth—that is, if a line were drawn from
the south pole, through the Earth, through the north pole and out into space, it would point approximately at
Polaris. Since the Earth spins on it’s axis, the entire sky appears to revolve around Polaris—one complete
“spin” every day. There are no significant deep sky objects in Ursa Minor.
Brightest Star
Polaris (North Star)
Pherkad Major
Sagittarius (sadge-ih-TAIR-ee-us) is located on the Milky Way. It is one of the
twelve constellations that make up the Zodiac, the most distinctive aspect of
Sagittarius is the group of stars (asterism) within it, which look like a teapot,
complete with spout and handle. Sagittarius is often thought to represent a
centaur, half man, half horse, and is usually considered to be Chiron,
identified with the constellation of Centaurus. However, Sagittarius holds a
drawn bow which is aimed at Scorpius, not in character with Chiron who was
known for his kindness and wisdom. Some say that Chiron was created to
guide Jason and the Argonauts as they sailed on the Argo.
Many deep sky objects reside in Sagittarius, including 15 Messier objects and
the Milky Way’s brightest star clouds—and the center of our galaxy. There
are open and globular clusters, nebulae, variable stars, double stars and galaxies—much to see—even with
binoculars. It lies low in the northern summer sky, however, and is best observed during the summer months.
The complex radio source Sagittarius A also eminates from this area. Astronomers believe that it is associated
with a supermassive black hole at the center of the galaxy.
Brightest Stars
Magnitude Open Clusters
Globular Clusters Planetary Nebula Nebulae
Kaus Australis
NGC 6494 (M23) NGC 6626 (M28) NGC 6818 (M17) NGC 6514 (M20)
NGC 6520
NGC 6531 (M21) NGC 6656 (M22)
Kaus Meridionalis
NGC 6530
NGC 6637 (M69)
NGC 6715 (M54)
Kaus Borealis
NGC 6613 (M18) NGC 6681 (M70)
IC 4725 (M25)
NGC 6809 (M55)
NGC 6716
NGC 6864 (M75)
NGC 6523 (M8)
NGC 6618
The Constellation Seasons:
Learning the constellations can be a daunting task since many of the star groupings are faint and mostly do not
really look at all like the “pictures” they represent. One way to keep the task manageable is to learn a few at a
time. Since only a few of the constellations are circumpolar from our location (visible all year long as they
rotate around the north star), it can be helpful to study the constellations by dividing them up according to the
seasons that they are visible. After all, it is much easier to become familiar with Virgo in the late winter and
spring months when it is visible in the night sky than it would be if it could not be seen at all—such as in the
summer or fall. There are many sources of information that look at the constellations in this way—especially
on the internet and in many notable books. The following constellations are listed by the season in which they
are prominent in the northern hemisphere. Obviously, many will overlap seasons and will be visible somewhat
The Spring Constellations:
Canes Venatici
Coma Berenices
Serpens Caput
Serpens Cauda
Ursa Major
Ursa Minor
The Herdsman
The Hunting Dogs
Berenice's Hair
The Crow
The Dragon
Hercules, the Hero
The Scales
The Wolf
The Serpent Bearer
The Scorpion
The Serpent's Head
The Serpent's Tail
The Great Bear
The Little Bear
The Virgin
The Summer Constellations:
Corona Australis
Coronas Borealis
Piscis Austrinus
The Water Bearer
The Eagle
The Sea Goat
Cepheus, a King of Ethiopia
The Southern Crown
The Northern Crown
The Swan
The Dolphin
The Little Horse
The Lizard
The Harp
The Flying Horse
The Southern Fish
The Arrow
The Archer
The Shield
The Little Fox
The Autumn Constellations:
Andromeda, daughter of Cepheus
The Ram
The Charioteer
The Giraffe
Cassiopeia, the Queen of Etheopia
The Whale
The River Eridanus
The Hare
The Hero
The Fish
The Sculptor
The Bull
The Triangle
The Winter Constellations:
Canis Major
Canis Minor
Leo Minor
The Crab
The Big Dog
The Little Dog
The Cup
The Twins
The Water Monster
The Lion
The Little Lion
The Lynx
The Unicorn
The Hunter
The Sextant
A Word About Binoculars:
For most of the history of humans on earth, astronomy was practiced using nothing more than the naked eye.
It wasn’t until Galileo invented the telescope that we were able to “see” with considerably more depth and
understanding the wonders of space. In these modern times, anyone with a few dollars can purchase a pair of
binoculars that would absolutely amaze Galileo and his contemporaries. A simple pair of $20 binoculars and a
desire to see a little more than you otherwise could without them—will bring a whole new universe into view.
Find the constellation Vulpecula and look through the binoculars and the “Coathanger” asterism appears. Look
at the Pleades in the constellation Taurus—you will see more than seven “sisters,” as well as some whispy
nebulosity. Zero in on the dim “smudge” in the constellation Andromeda and a spectacular view of our nearest
galaxy appears. In the early evening or pre-sunrise morning, the planet Venus can be a spectacular sight—as
is distant Jupiter with it’s four easily-seen Galilean moons. There is a lifetime of surprises and wonder “up
there” for anyone willing to look up through binoculars. …and if it leads to a more serious hobby or pastime,
well…there are worse problems, to be sure.
To show proficiency in this topic, it is suggested that one should demonstrate a general knowledge of the
constellations; their history, lore, and reason for being. Familiarity with any 12 constellations from at least two
seasons is considered adequate. A general description of the Zodiac and the definition of asterisms—along
with at least 3 examples is required. And lastly, the ability to point out and identify the 12 constellations and 3
asterisms in the night sky to a fellow StarSplitter who has already passed this proficiency level.
Suggested Sources to learn more: (Click on “StarGazing” for lots of StarSplitters and Astronomy information) (a very good discussion of the constellations—and some good links to
other constellation related sites) (a clickable list of links to all the 88 constellations) (a large database with extensive deep sky information) (a complete list of the constellations with clickable links to
each one—with star charts)
Please watch the excellent Filippenko “lessons” on the VHS or DVD media in the StarSplitters library.