First of all, what is a constellation?
Before we take a deeper look at the Capricornus constellation, lets first explore just exactly what a constellation is. Basically, it’s a group of Stars, clusters, nebulae and other objects in the night sky. A constellation is an area on the celestial sphere (an imaginary sphere) where a group of visible objects are located.
These stars and objects typically form a pattern or outline, which we perceive to represent an inanimate object, (like a pan flute or question mark), an animal (like the goat,) a mythical person (like Pan, the god of the wild, shepherds and flocks from Greek mythology) or even a type of creature (half fish and half goat, the sea-goat or goatfish)
It is also an astronomy term used to describe a variety of groups of stars that have been given a specific name such as:
Constellations are constantly moving and move in the direction from East to West.
The Capricornus Constellation – Facts in brief:
The Capricorn Constellation (Capricornus) is one of the 12 constellations of the zodiac, and ranks the 40th largest of the 88 modern constellations seen in the night sky.
Capricornus (its Latin name) is quite easy to recognize, as it clearly resembles the outline of a mythical creature that is half fish and half goat, if you join the dots. It is symbolized as a Sea-Goat.
‘Capricornus’ means horned goat, Goat horn or even having horns like a goat in Latin.
Where is the Capricorn Constellation Located?
Capricornus is positioned in the fourth quadrant of the Southern Hemisphere, or is sometimes referred to as being located in the SQ4 Quadrant.
Where can it be seen?
Co-ordinates of a right ascension, or left ascension and their declination are used to locate all of the Constellations, like Capricornus.
The Stars of Capricornus can be observed from Earth in the Northern Hemisphere in summertime and in the Southern Hemisphere in wintertime.
Even at its highest it remains close to the southern horizon when viewed from Northern latitudes.
In the Southern Hemisphere
The Constellation Capricornus is found at around 20 hours, 6 minutes to 21 hours, 59 minutes right ascension and an -8.4 to -27.69 degree declination, in the Southern Sky.
Visibility from the Northern Hemisphere
It’s visible in the Northern Hemisphere at latitudes between +60 degrees and – 90 degrees and covers an area of 414 square degrees in the sky.
How can you identify the Capricorn Constellation?
The simplest method for spotting any particular Constellation of the Zodiac from Earth is to first of all locate the brightest star in that Constellation, and then look at the neighboring illuminations, to see if you can identify a recognizable pattern.
Capricornus is represented as the celestial Sea Goat.
The Star System of Capricornus
The brightest star in Capricornus is called Deneb Algedi (Delta Capricorni or Del Cap). It is actually a multiple star system, with 3 stars within it, but is not regarded as the Alpha Star in Capricornus.
It’s located 39 light years from The Sun and has a magnitude of 2.9.
The 3 Stars in this star system include:
- Delta Capricorni Aa (the primary Star),
- Delta Capricorni Ab
- Capricorni C.
Within the Deneb Algedi star system the primary star is actually a White Giant.
Delta Capricorni Aa is an eclipsing binary star with Delta Capricorni Ab.
It is the combined light of the various bright stars in this star system that produces enough light to give Deneb Algedi the brightest star status in the Constellation of Capricornus.
Spotting Capricornus in the night sky
The easiest way to spot the Constellation of Capricornus would be to locate the Bright Star Deneb Algedi (Delta Capricorni) in the Southern sky.
The next step is to try to imagine the surrounding shape of the goat-fish, by joining the illuminated dots (the other Stars).
This simple technique can be used to spot other Constellation patterns too like the Question Mark or the tail of a fish.
The name of the Star ‘Deneb’ is Arabic and means the ‘tail’, and traditionally Deneb means the tail of the goat. This name represents the position of this star in the recognizable image of the Sea-goat.
The Constellation Capricornus is located very close to the Constellation Sagittarius.
Capricornus can be spotted from both the Northern Hemisphere (north of the equator) in the Southern Sky, and from the Southern Hemisphere (south of the equator) in a much higher position in the Northern sky.
It has been described as having an outline like a squashed triangle.
So, if you find the Constellation Sagittarius, then look across to the left and find a long diagonal line that lies along the ecliptic, with two triangles dangling from it, that’s Capricornus!
FACT: The ecliptic is the imaginary line tracing the route that The Sun, the Moon, and the Planets take across the sky over the year.
The summer triangle
Another way to find the Goat –fish shape of Capricornus is to find the ‘summer triangle’ asterism in the night sky.
The Summer Triangle has a star at each point: named Deneb, Vega and Altair.
If you draw a line from the Vega Star towards Altair and continue in a straight line you will locate Capricornus.
The best months to spot the Constellation of Capricornus, the Sea Goat, in the Northern Hemisphere is from September to October.
The best time of day to spot it is around 21.00 at night (22.00 Daylight Saving Time) local time around the world.
Capricornus is at its highest in the sky early September, but as time approaches the period when the Sun houses Capricornus, late December, January it begins to fade.
When viewed from the Southern Hemisphere Capricornus appears upside down!
How is it formed and named?
The Constellation of Capricornus ranks as the 40th biggest in the sky but the second smallest zodiacal constellation in the Southern Celestial Sky, and it fills an area of 414 square degrees.
It has a simple and easy to identify shape like ‘Sea-Goat” which is the front half of a Goat and the back half of a Fish (with the horns of a Goat and the tail of a fish).
It is formed by the positions of the 3 main stars that make up the Constellation of Capricornus.
The main Stars in Constellation Capricornus
There are many different Stars within the Constellation Capricornus.
The named stars of Capricornus, range in luminosity from the brightest Star (the Deneb Algedi, also known as Delta Capricorni)
- Deneb Algedi (the brightest Star in Capricornus, and a White Giant. It is located around 38-70 light years from The Sun, and hotter than the Sun)
- Dabih (the second brightest Star in Capricornus, and is actually a star system, including Dabih Major and Dabih Minor)
- Alshat (Nu Capricorni) is a binary star
- Algiedi (is an optical binary star with another Arabic name, meaning Billy Goat)
- Nashira (a Blue white giant, meaning the bearer of good news)
The importance of the Constellation Capricornus dates back as far as the Babylonians and the Sumerians. Both these ancient civilizations referred to Capricornus as the goat-fish.
Who, or what represents Capricornus? –
The Constellation Capricornus, is represented by – the Sea-Goat
The reason is that it looks very similar to the outline of a mythical creature that has the head and front of is body as a Goat and the back and tail of a fish. The outline of Capricornus is easily recognized in the night sky.
How do the Bright Stars of Capricornus form the shape of a goat with the tail of a fish?
The Bright Stars
If you look up and into the night sky you can imagine the recognizable outline of the Constellation of Capricornus, which is a celestial avatar of a Sea-Goat, (half fish and half goat) and the different parts of its body. represented by other stars.
Stars with Planets
Capricornus also has 5 Stars with Planets orbiting around them in the solar system but they are unlikely to be able to support life forms.
Stars without Planets
Capricornus has further cataloged Stars with no planets.
The Constellation Capricornus a total of 8 main Stars.
Not all the stars within the Capricornus Constellation are visible to the naked eye but with telescopes and modern imagery techniques is it possible to glimpse all of the stars.
When was the Capricorn Constellation first discovered? –
The Greeks were the first ancient culture to name the 88 Constellations in the sky.
They were each given 3-letter abbreviations to help identify them and the Stars within those Constellations are also referred to by those 3-letter codes.
It was the Greek Astronomer – Ptolemy, who first cataloged the Constellation of Capricornus, in the 2nd Century (2 AD.). Ptolemy listed the various constellations in his Almagest (a book recording astronomical data).
When referring to a Star within a Constellation it is given the genitive form of the Constellation name. (‘Capricorn’ with ‘i’, to give ‘Capricorni’)
For example, within the Constellation Capricornus the Stars would be referred to by a name or a letter from the Greek Alphabet (in order of brightness) followed by ‘Capricorni’, such as:
- Delta Capricorni (Deneb Algedi) – the brightest Star in the Constellation
- Beta Capricorni (Dabih) – the second brightest Star and is a double star (Dabih Mayor and Dabih Minor). The name Dabih means ‘the Butcher’ in Arabic
- Alpha Capricorni (Algiedi) – is an optical double star coming from Prima Giedi and Algiedi (themselves made out of other stars)
- Gamma Capricorni (Nashira) – is an Am star and classified as a variable star too
- Zeta Capricorni (Yen) – is a binary star
- Theta Capricorni (Dorsum) – is an A-type main sequence star
- Omega Capricorni (Baten Algiedi) – is an M-type red giant star
- Psi Capricorni (a yellow – white giant star) is an F-type main sequence star
The Constellations change their positions throughout the year as the Earth rotates around the Sun.
This means our position in space is forever changing and as a result our view of what’s in space changes too, and will continue to do so.
Why and what is the purpose of Capricornus? –
In ancient times the dots, bright lights and perceived objects in the sky were of great interest and the makings of folklore to a great range of people from seamen to farmers.
From children to the elderly, we have had an ongoing fascination, with our solar system and star system. Perhaps it’s because the enormity and variety within it makes us realize just how large and exciting the universe is.
FACT: The Star System or Stellar System is a small number of stars that orbit around each other and are bound together by gravity. When it becomes a large group of stars, again bound together in the same way, by gravity, it is known as a Galaxy or Star Cluster.
Whether they contain small groups of stars or larger groups of start the both come under the classification of ‘Star System’.
The Constellations in the night sky were a useful navigation tool and guide as well as the subject of legends and myths, about heroes like Zeus, Pan and other powerful gods.
42 of the Constellations have been named after animals with a story behind each name.
Background & Facts:
Part of the Zodiac
The Constellation of Capricornus found in the Southern Sky, is one of the smallest constellations of the zodiac, only Cancer is smaller.
When the zodiac ‘ring’ or ‘belt’, of constellations is listed in order, as the 12 astrological zodiac signs (months) of the calendar from January to December, it lists as:
In the order of the vernal equinox (where the ecliptic meets the celestial equator) the order of the signs begins with Aries, the first, and then and runs through to Pisces. In this series Capricorn is the 10th sign of the Zodiac.
However you categorize the list of the Constellations of the Zodiac, each Constellation in the belt, like Capricorn, has two immediate Constellation neighbors – one in front (e.g. Aquarius is in front of Capricorn) and one behind it (e.g. Sagittarius is behind Capricorn).
Hiding in the house
The constellations in the Zodiac ‘belt’ forms an imaginary ring that’s closely aligned to the orbit of Earth. As a result each of the 12 zodiac constellations has a cycle that passes through the Sun (the biggest and brightest Star, that is actually a Dwarf Star not a Giant Star).
The Sun is then said to house (hide) each Constellation in turn. Our Sun ‘houses’ a different Constellation each month and then you cannot see that particular Constellation.
The Sun passes through the sign of Capricorn between December 21 and January 20. This is about one month before the Sun passes through the Capricornus constellation. At this point Capricornus would be referred to as hiding in the house of Capricorn.
Until 130 BCE the winter solstice in the Northern Hemisphere used to take place when the Sun was in the Constellation Capricornus. Even though this no longer happens the astrological sign of Capricorn is still used to describe the position of the winter solstice.
The latitude of the Sun’s most southerly position is known as the ‘Tropic of Capricorn’. The Tropic of Capricorn is also used to describe the line on Earth where the Sun is directly overhead at local noon on the December (Southern) solstice day.
The neighbors of Constellation Capricornus
The Constellation of Capricornus is neighbored by several constellations in the Northern Sky: Constellation Sagittarius is the guide point for finding Capricornus in the sky.
The other neighbors include Aquarius, Aquila, Microscopium and Piscis Austrinis.
Within Constellation Capricornus
The Constellation of Capricornus is formed by of a number of different components.
The different components housed by the Constellation Capricornus are mainly Stars, Deep sky objects and Messier objects (galaxies).
There are many different types of Stars in the star system categorized by size, lifespan and luminosity.
Generally, larger Stars have a shorter lifespan.
Stars are formed from clouds of interstellar gas and include:
Red Dwarf Stars
Most of the stars in the galaxy are Red Dwarf Stars. They are small in size measuring about 40-50% of the mass of The Sun. They are cool and their luminosity has only about 10% of the brightness of the Sun (our brightest Star), and they live for longer.
Brown Dwarf Stars
These are known as failed stars that form like other stars but don’t reach the mass, heat or density to begin the nuclear fusion process. They are only about 8% of the mass of the Sun and are red not brown, and not easy to spot in the night sky.
Red Giant Stars
These are giant luminous stars that have a low or medium mass. Red Giant Stars are formed when a star expands its volume by fusing all of its hydrogen into helium, and then burning the helium to produce carbon and oxygen to expand.
These are giant, bright stars that range from 10-100 times the size of the Sun and are 1000 times brighter. They are big and hot and therefore burn out quickly. The biggest are called Blue super giants or hyper giants. The biggest ever discovered was about 10 million times brighter than the Sun,
These are main-sequence stars like the Sun, but only 80% of its size, and are bright stars,
These are small burnt out husks of stars, about the same size as the Earth. White Dwarfs are dense and represent the final state of evolution for a star, like most stars in the galaxy.
These are the remains of a White Dwarf after it cools and darkens. This is likely to happen after about 10 billion years of life.
These are also main-sequence stars like the Sun, but twice the size, and are bright stars and hot.
Other types of stars include Neutron stars, Variable Stars and Binary Stars
The sky is home to various bright stars.
The brightness of a star is measured by a value called its magnitude and they come in different sizes, composition, mass and color. Their vast distance away from us is measured in light years from either the Earth or the Sun.
The lower the magnitude value the brighter the star appears in the night sky when viewed from Earth.
FACT: The Sun is considered to be the brightest star in the sky.
Capricornus has 5 named stars that host planets within the Constellation Capricornus that have been officially approved by the International Astronomical Union (IAU):
As well as Stars, the Capricornus Constellation also has deep sky objects and galaxies (or even globular clusters).
Deep Sky Objects
FACT: A Deep Sky Object is an astronomical object, that is not a solar system object like the Sun, Moon, Comet or a Planet. An individual Star is not considered to be a Deep Sky Object.
Deep Sky Objects are faint objects that can still be observed by the naked eye in the night sky from Earth.
They include Galaxies, Star Clusters and Nebulae.
What is a Nebula?
A Nebula is a massive cloud of gas and dust in Space.
Some Nebulae are formed when a star explodes and then dies, as is the case with a Supernova. Sometimes they can act as Star nurseries and are the areas where new Stars are forming.
The Nebulae are the spaces in between the stars referred to as interstellar space.
Images of the Nebulae have been captured using professional Space telescopes, such as the NASA Spitzer Space Telescope, operated by NASA, and the famous Hubble Space Telescope.
There is only one Messier object within the Capricornus Constellation and it is named ‘Messier 30’.
Charles Messier, a French astronomer, is credited with discovering Messier 30 in 1764. He is famous for publishing an astronomical catalogue that lists 110 nebulae and star clusters.
These later became known as the Messier objects.
Messier 30 (M30) is a globular cluster found in Capricornus. This cluster is some 27,140 light years from Earth.
It has a magnitude of 7.7 and the designation of NGC 7099 within the Messier catalogue.
The best time of year to view Messier 30 is in August.
NGC 6907 (a spiral galaxy) and HCG 87 (a large Galaxy Group) are also found in Capricornus.
FACT: A star cluster is a large group of Stars, of which there are 2 different types in Capricornus:
- Globular Clusters:
A global cluster is a spherical collection of ‘Old Stars,’ numbering hundreds to millions, that are tightly bound by gravity and orbits a galactic core.
- Open Clusters:
An open Cluster is a looser formation of ‘Young Stars’ that generally has less than a few hundred Stars.
What is the Milky Way?
The Milky Way is a Spiral Galaxy, containing over 200 billion Stars, and forms part of the Constellation of Sagittarius. The Milky Way itself is not a Constellation of Stars.
This is the Galaxy that contains our solar system and it gets its name from the fact that it looks like a hazy swirl or river of milk across the sky, when viewed from earth.
It is made up of Gas, Dust and Stars, with spiral arms wrapped around it, and a massive black hole in the center of the Galaxy. Not all of the Stars in the Universe are contained within the Milky Way.
It is at its brightest if looking towards the galactic center in the direction of Sagittarius.
The Stars that make up the Milky Way are many light years away and cannot be individually identified by the naked eye.
Historical significance: the legends, and myths surrounding Constellation Capricornus
When it comes to the many recognized constellations in the sky, Constellation Capricornus is one of the oldest known.
When Ptolemy, the Greek astronomer, catalogued Capricornus as far back as the 2nd century, it became a topic of great interest in Greek mythology.
There are many Greek myths and legends surrounding the origin and names of the constellations, involving gods like Zeus and even mythical creatures like ‘Amalthea the Goat’.
It is said that Amalthea the Goat suckled Zeus after his mother Rhea rescued him from Cronos his father who wanted to kill him when he was young.
In Greek mythology, The Greeks associated Capricorn with their god Pan, while other cultures associate Capricorn with the Sea-Goat.
One myth involved ‘Pan’, the brave forest deity.
Pan was a strange–looking deity who had the legs of a Goat, but from the waist up he was a man with the ears and horns of a Goat. During the war with the Titans it was Pan who came to the rescue of other gods and was rewarded by Zeus and given a place in the sky. He helped to scare the Titans away by blowing his conch shell and then warned the other gods that Typhon was coming.
Typhon was a monster sent by the Titian Gaia to destroy the gods, so Pan told the gods to disguise themselves as animals to fool the monster. Pan escaped from the monster Typhon by turning his lower body his into a fish jumping into the River Nile, and Zeus was then able to kill the monster.
Following the theme of this myth the image of Capricornus is a goat with a fish tail.
The story continues in the sky, with the son of Pan called Crotus, who is represented by the Constellation Sagittarius who is the neighbor of Capricornus.
Or, as another myth goes Capricornus could have been Amalthea, the goat that fed baby Zeus while he was in hiding from Cronos the Titan who was his father.
The Medieval magic rituals
There are 15 Behenian Fixed Stars, which formed a group or circle of Stars used in magic rituals as far back as the Medieval Times. Delta Capricorni (Deneb Algedi) is one of the Behenian Stars.
The Mesopotamian civilization (the first known civilization) identified a constellation like Capricornus
FACT: The ancient lands of the Mesopotamians now stretches across Turkey, Syria, Iraq and Kuwait
For thousands of years, various cultures around the world have identified and named the constellation we know and see in the night sky as Capricornus.
The Babylonians also recorded details of various bright stars within the constellations in their Babylonian star catalogues before 100BCE. They also associate their god ‘Ea’ with the image of the Goatfish.
What is the ‘Big Dipper”?
When we take an interest in the different objects in the night sky one of the first patterns we learn to recognize is the ‘Big Dipper’.
The Big Dipper is not a constellation it is an asterism.
In fact, The Big Dipper is the best-known asterism and one of the most easily recognized patterns in the northern sky at night. It is within the Constellation Ursa Major (the Great Bear).
The Big Dipper is known by different names across the world but it is the same arrangement of stars forming the pattern. It is also known as:
- The Plough, the Saucepan, and the Great Wagon
What is the difference between a constellation and an asterism?
An asterism is a group of stars that appear to form a pattern in the night sky but with no officially determined boundaries.
It can make up part of a constellation or cross the boundaries of an official constellation or even a defunct constellation.
An asterism is a more vague assembly of stars than a recognized constellation.
Characteristics of Capricorn
The constellation of Capricornus is one of the 12 constellations of the Zodiac and as such is represented by the birth star sign of Capricorn.
Capricorn is an Earth sign.
We know what Capricornus looks like in the night sky in the Southern Hemisphere but what are the typical personal characteristics of someone born under the zodiac sign of Capricorn like?
Characteristics of people born within the Capricorn
The Star sign of Capricorn includes people born between, December 23 to January 20.
Capricorn is one of the 4 cardinal signs of the Zodiac: Capricorn, Aries, Cancer and Libra. They are sometimes referred to as the ‘reacting signs’.
It is believed that people born under one of these signs will have certain traits and behaviors.
The typical characteristics of a Capricorn person, is related to having a very structured and independent nature and being highly ambitious.
Negative traits: They often don’t trust others to do things for them correctly, are natural born leaders, highly ambitious but sometimes considered to be boring or over serious.
Positive Traits: Capricorns are thought to be loyal and patient. They are resourceful and can act quickly in a variety of situations.
Ancient associations with Capricornus
The Greeks, the Romans and the Sumerians all had an interest in the constellations in the sky.
The Sumerians were the first literate civilization of the Ancient Mesopotamia (an area occupying parts of Turkey and the Syria of today, Iraq, Iran)
The Sumerian civilization was not unified like the ancient Greek or Roman civilizations it was bonded by a common attitude.
Their belief systems featured many deities. They regarded their gods as being responsible for everything and as such held them in great respect. Many stories arose as a result.
As an earth element Capricorns can also be focused, grounded and reliable.
It’s make up – Capricornus is an easy Constellations to spot in the night sky because of its distinctive outline of a Goat-fish creature.
The meteor showers
The Capricornus Constellation is associated with 5 meteor showers known as the Capricornids.
The 5 meteor showers are:
- The Alpha Capricornids
- The Chi Capricornids
- The Sigma Capricornids
- The Tau Capricornids
- The Capricornids-Sagittarids
The Alpha Capricornid meteor shower occurs between July 3 and August 15, with its peak on July 30 every year.
Fun Facts about Capricornus – Did you know that?
- Even though Capricornus, the Sea-Goat, is a relatively faint constellation it is not the faintest of the 12 Zodiac Constellations. The constellation of Cancer is recognized as the faintest constellation of the Zodiac.
- The proper astronomical name is Constellation Capricornus as distinct from the name ‘Capricorn’which is its corresponding name of the astrological sign of the Zodiac, and is symbolized by the mountain Goat.
- The Constellations are not part of the solar system; they are groups of stars that appear to form shapes that are visible from Earth.
- The largest Constellation is called Hydra and the smallest Constellation is called Crux.
- A Constellation does not actually exist as a fixed object, it is a group of bright stars that happen to be in a random place and are light years apart and ever moving. We see the pattern of their presence.
- Capricornus the Latin name, for this Constellation has been recognized as the shape of a hybrid of a Goat and a fish by many ancient cultures including the Persians, the Mesopotamians, the Greeks, the Babylonians, the Syrians and the Turks.
- The Star Psi Capricorni is hotter, larger with bigger mass than the Sun.
- Constellations are not found in the Solar System. There are various objects within our Solar System from Planets to new planetary-mass objects that have been classified as Dwarf Planets.
- The center of a Galaxy does not contain a Giant Star it contains a massive Black Hole.
- Spiral Galaxies make up about two third of all the Galaxies in the Universe
- Saturn is the ruling planet of Capricorn and it believed to make Capricorn’s natives disciplined and strict.
- The 12 signs of the Zodiac are celebrated in many ways, e.g. The Makara Sankranti festival in India celebrates Capricorn
Commonly Asked Questions
Q. What is the celestial sphere?
A. In astronomy and navigation terms, the celestial sphere is imaginary.
This virtual sphere has a large radius that is concentric with Earth.
We can imagine all objects in the night sky as being projected upon the inside of this celestial sphere, as if it has images placed inside a dome.
Q. What prevents us seeing the Stars and Constellations in the night sky?
A. Light pollution, fog, city lights and artificial lights all limit our visibility of the objects in the sky at night.
The best views come from outside of cities where light pollution is less. Camping in the countryside is one of the best ways to get a better view of what’s up there in Space.
Q. Will the Constellations change over time?
A. The Constellations are continually on the move.
The images we form in our imagination to make objects, shapes and patterns out of the constellations have already shifted over time.
As we view the night skies from Earth they are likely to continue to shift and possibly in time the images may look very different.