First of all, what is a constellation?
Before we dive deep into the Chamaeleon constellation, let’s first define what a constellation is.
Basically, it’s a group of Stars. A constellation is an area on the celestial sphere (an imaginary sphere) where a group of visible stars are located.
These stars typically form a pattern or outline, which we perceive to represent an inanimate object, (like the Plough), an animal (like the chameleon, or Lion), a mythical person (like the Hunter), or even a type of creature (like Phoenix, or Cetus), from Greek mythology.
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 Constellation Chamaeleon– Facts in brief:
What is it? –
The Chamaeleon Constellation is regarded as a small and dim constellation in the Southern Hemisphere.
It is listed as the 79th largest Constellation filling around 0.3% of the night sky and is one of the southern most Constellations we know about.
The most southern Constellation its neighbour called Octans.
The Chamaeleon Constellation is thought to resemble the shape of the chameleon, a sort of lizard, from the position of its four bright Stars, in the Southern Sky.
The name ‘Chamaeleon’ is Latin for the Chameleon and its Latin genitive ‘Chamaeleontis’ is sometimes abbreviated to ‘cha’.
It is best seen in the month of April.
Where is it located? –
The Chamaeleon Constellation is positioned in the second quadrant of the Southern Hemisphere, south of the ecliptic plane (which is different from the celestial equator).
Being located south of the celestial equator makes it more visible from the Southern Hemisphere.
It is sometimes referred to as being located in the SQ2 Quadrant.
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.
Chamaeleon is located very close to the south celestial pole (which is positioned in neighboring Constellation Octans).
The Constellation of Chamaeleon is not considered to be a circumpolar constellation as it is not visible from all locations throughout the year in Southern latitudes.
However it is visible from Sydney, in Australia all year round, while in other parts of Australia like Darwin, it disappears from view from September and October.
The true Circumpolar Constellations
There are 5 Constellations that are visible throughout the year, from most locations located north of the celestial equator, making them Circumpolar, they are:
- Cassiopeia Constellation
- Cepheus Constellation
- Draco Constellation
- Ursa Major Constellation
- Ursa Minor Constellation
FACT: A constellation that is visible all year round is known as a Circumpolar Constellation.
There are 3 Southern Constellations that are also circumpolar –
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 Chamaeleon.
The Chamaeleon Constellation lies at an 11 hours right ascension, and a declination of 80 degrees South.
It’s visible at latitudes between 0 degrees and -90 degrees and covers an area of 132 square degrees in the Southern sky.
How was it formed, found and named?
Sea navigators, explorers, astronomers, and cartographers, throughout the ages, have observed the Constellations.
The Dutch influence
It was in the 16th Century, around 1595, that the first Dutch sea voyage to the East Indies took place.
These voyages enabled Dutch navigators and cartographers Pieter Dirkszoon Keyser and Frederick de Houtman, (students of Petrus Plancius) to make astronomical observations on their sea voyages of the bright stars and constellations in the night sky.
It was on one such voyage to the East Indies that Pieter Dirkszoon Keyser catalogued around 130 Stars and recorded 12 new Constellations in the Southern Celestial Sky.
It was in fact the Dutch astronomer Petrus Plancius who is credited with the creation of this constellation and introduced it to the world in the late 16th Century as Keyser had died before returning from this voyage.
Perhaps it was Keyser’s colleague Frederick de Houtman who helped his tutor Petrus Plancius to name the Constellations from these observations on his return from the East Indies voyage.
This Constellation Chamaeleon was perhaps named after the Chameleon, a type of lizard known to change the color of its skin to camouflage itself and blend into its local surroundings.
It is possibly in reference to indigenous reptiles seen during their travels to the East Indies.
Petrus Plancius and Jodocus Hondius depicted the Constellation of Chamaeleon in the shape of a Chameleon on a celestial globe in 1592
Later, in 1603, the Constellation of Chamaeleon was listed in Johann Bayer’s Uranometria. (Uranometria is a well-known Star Atlas compiled by German astronomer Johann Bayer).
Chamaeleon fills an area of 132 square degrees.
- Initially, the shapes of their star patterns informally categorized the
- Eventually, the International Astronomical Union (IAU) published the official listing of constellation boundaries, mapping the constellations by their sky coordinates not by their line patterns and shapes.
The Chamaeleon Constellation is one of the 88 Constellations within the celestial sphere listed in the official IAU chart published by the International Astronomical Union (IAU).
How can you identify The Constellation Chamaeleon?
The simplest method for spotting any particular Constellation 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.
Meet The Neighbors
The Chamaeleon Constellation is bordered by several other Constellations:
- Musca, Crux, Carina and Volans – to the North
- Mensa – to the East
- Octans – to the South
- Apus – to the West
It is most visible in the Southern Hemisphere in the evening around 21.00 hours, during the month of April, but because the stars are in different locations and different distances it is not possible to go one location to view it.
The Constellation of Chamaeleon is not located close enough to the Milky Way for it to be associated with the Constellations that are visible by the naked eye in its swirl of light.
The Stars in Chamaeleon
There are no very bright Stars, and no named bright Stars, in this Constellation.
The brightest Star in Chamaeleon is known as alpha Chamaeleontis, and has a magnitude of 4.1, this level of illumination gives it a fourth magnitude Star rating (there are no Stars with an apparent magnitude brighter than +4.0, located within this faint Constellation)
There are only 4 main Stars prominent in the outline of the Chamaeleon Constellation, however it has a total of 16 Stars that have been classified under the Johann Bayer Flamsteed system of naming Stars in the night sky.
The brightest Stars in any Constellation are listed and named in order of luminosity, using the Bayer designation system, from the brightest Star to the faintest Star.
Quick Facts about Chamaeleon:
- In the Constellation of Chamaeleon the brightest Star is named, Alpha Chamaeleontis. It is a white-hued Star, located around 63 light years from Earth. Alpha cha has an apparent visual magnitude of 4.2, and is visible by the naked eye.
- The second brightest Star is called ‘Beta Chamaeleontis’, a blue-white hued Star that’s around 271 light years from Earth it has an apparent magnitude of 4.2, also visible by the naked eye.
- The 4 bright Stars forming the outline shape are alpha Chamaeleontis, beta Chamaeleontis, gamma Chamaeleontis, and delta Chamaeleontis.
- Chamaeleon does not have any Stars ranked in the 100 brightest stars in the solar system
- The dimmest Star DR Chamaeleontis, which can just about be seen by the naked eye has an apparent magnitude of 5.97.
- The closest Star HIP 66125 is located only 58.5 light years from Earth
- The furthest Star HIP 64554 is located around 29651.2 light years away from Earth
- There are 19 Stars in Chamaeleon that are visible by the naked eye in a clear dark night sky. Although none of its Southern Stars have an apparent magnitude greater than a fourth magnitude classification.
- A total of 370 Stars have been identified and scanned by the Hipparcos satellite but not all are visible by the naked eye.
FACT: it is assumed that the dimmest Star visibly the naked eye is one with a magnitude of +6.0 (although some references say the apparent magnitude for naked eye visibility of a Star is as much as +6.5)
The Chamaeleon Constellation can be identified as a diamond shape, symbolising a lizard, from the positions of the 4 brightest Stars.
The Star System within Chamaeleon
There are no named Stars within Constellation Chamaeleon.
FACT: Star names come from many different cultures and their stories and beliefs. Many Star names date back to ancient times and are still used today. All of the official Star names have to be approved by the IAU, and most traditional Star names are in Arabic.
The Constellation of Chamaeleon does not have any formally approved named Stars.
The Location of Chamaeleon
This Southern Constellation can be spotted in the Southern Hemisphere, also referred to as the Southern celestial sky.
The Constellation Chamaeleon is surrounded by various recognizable Constellations namely
- Apus; Octans; Carina; Mensa; Musca; Volans and Crux.
The identifiable outlines of these Constellations are used as a guide-point in the sky used by astronomers and amateur stargazers to identify certain Deep Sky Objects of interest.
The naming of Chamaeleon Constellation
Chamaeleon is usually associated with the name ‘the Chameleon’, and sometimes the long lizard.
It was the Dutch astronomer Petrus Plancius who is credited with creating and naming the Constellation of Chamaeleon.
Chamaeleon is a member of ‘the Johann Bayer family of Constellations that includes (in alphabetical order):
What’s within the Chamaeleon Constellation?
The different components are mainly Stars, Deep Sky Objects and Messier objects (galaxies).
The Constellation of Chamaeleon is formed by of a number of different components, it has:
- 3 main Stars
- 3 associated exoplanets
- 0 formally named Stars
- 1 associated meteor shower
- 0 Messier Objects
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. A Red Giant Star is 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 the Orange Giant, Neutron stars, Variable Stars and Binary Stars
What is a Bright Star?
The sky is home to various bright stars.
The brightness of a star is measured by a value called its magnitude (apparent magnitude) and they come in different sizes, composition, mass and color.
Their vast distance away from us is measured in light years from the Earth, the Sun or even the Milky Way.
The lower the magnitude value the brighter the star appears in the night sky when viewed from Earth.
Locating its 4 brightest Stars, alpha Chamaeleontis, beta Chamaeleontis and delta Chamaeleontis can identify Chamaeleon as a long diamond shape that could resemble a long thin lizard.
As well as Stars and Star Clusters, the Chamaeleon Constellation also has deep sky objects and galaxies (or even globular clusters or open clusters).
Deep Sky Objects
The notable deep sky objects, includes objects from the Henry Draper Catalogue of Stars (abbreviated to HD and a designated number as an identifier), or the Index catalogue classification (IC)
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.
Deep Sky Objects include Galaxies, Star Clusters and Nebulae.
- Star clusters – such as Globular Clusters of Stars or Open Clusters of Stars
- Dark Nebula, Planetary Nebula, Diffuse Nebula, and Supernova remnants
- Galaxy Groups, Galaxies, Spiral Galaxies, Gravitational Lenses and Quasars
What is a Messier?
A Messier is a cluster of Stars
It was Charles Messier, a French astronomer, who is credited with cataloging each of the Messier Star clusters, around 1764.
He is famous for publishing an astronomical catalogue that lists 110 nebulae and star clusters, known as the New General Catalogue (used in its abbreviated form NGC and numbered).
There are no Messier object star clusters within Constellation Chamaeleon, but there are some NGC listed objects and notable galaxies:
FACT: A star cluster is a large group of Stars that can be Globular Clusters or Open Clusters:
- 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.
The Eta Chamaeleontis Cluster
The Eta Chamaeleontis Cluster, also known as Mamajek 1, is an open star cluster, with around 12 young Stars, located in the Constellation of Chamaeleon that is centered around the bright Star Eta Chamaeleontis.
It is thought to be around 8 million years old and located around 316 light years distant.
This was the first open cluster to be discovered due to the X-ray emissions emitted by its member Stars.
The Chamaeleon Cloud Complex
The name ‘Chameleon’ is associated with ‘changing appearance’ and ‘disguise’.
The Constellation Chamaeleon disguises itself with a large number of dark molecular clouds known as the ‘Chamaeleon Cloud Complex”. These clouds contain pre-main sequence Star candidates as well as low mass T Tauri Stars.
The southern area of the Chamaeleon Cloud complex is appears as a network of dark knots connected by wavy serpent-like filaments that reflect stellar light. These are considered to be very young Stars that are not at the stage where they could collapse and create a major star formation.
This is one of the closest low mass star forming regions to the Sun, and is situated about 15 degrees below the galactic plane.
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.
There are several types of Nebulae:
- Bright Nebulae,
- Emission Nebulae,
- Reflection Nebulae,
- Dark Nebulae,
- Planetary Nebulae
NGC 7049 (known as Caldwell 109) is a slightly oval shaped planetary nebula within Chamaeleon. It’s the most southerly known planetary nebula. It has an apparent magnitude of 11.6 and therefore is not visible by naked eye.
FACT: a ‘reflection nebula’ is an interstellar cloud that should be a dark nebula (a molecular cloud) however its dust reflects light from a nearby bright star and it reflects the light, hence the name.
Images of the Nebulae have been captured using a professional large telescope, such as the NASA Spitzer Space Telescope, operated by NASA, and the famous Hubble Space Telescope.
Chamaeleon is often abbreviated to ‘Cham’ from a naming convention used by NASA.
A supernova remnant is the structure that’s left after a star explodes in a supernova.
There are 3 types of supernova remnants: shell-like, composite and mixed-morphology (or thermal composite).
What is the Milky Way?
The Milky Way is a Spiral Galaxy, containing over 200 billion Stars, and actually forms part of the Constellation of Sagittarius.
The Milky Way itself is not a Constellation of Stars. It 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.
Background & Facts:
The Greeks were the first ancient culture to name the early modern Constellations in the sky.
It was unlikely that the ancient Greeks or Romans would have spotted the Constellation of Chamaeleon, as it is located too far south. It was only sea voyagers at that time that could view the most southern constellations.
It was the well-known Greek Astronomer – Ptolemy, who first cataloged the 48 early constellations, in the 2nd Century (2 AD.), but he did not catalogue the Constellation of Chamaeleon.
In 1603, The German Astronomer – Johann Bayer, systematically assigned names to the brightest stars in each constellation and cataloged them in his Star atlas – ‘Uranometria Omnium Asterismorum’.
The Bayer designations are stellar designations where the stars within Constellations are initially identified by a name or a letter from the Greek Alphabet from Alpha through Omega (in order of brightness).
1. The names of the Stars begin with a letter of the Greek alphabet starting with– Alpha, then beta, gamma, etc.
2. Followed by the genitive form of their parent constellation’s Latin name – ‘Chamaeleontis’
3. Giving the first Star name ‘Alpha Chamaeleontis’
The main stars of Chamaeleon are named by their apparent magnitude (luminosity) from the brightest to faintest star in decreasing order, Stars with an apparent magnitude of less than +5.07 include:
1. Alpha Cha – an apparent visual magnitude of 4.05
2. Gamma Cha – a variable visual magnitude of 4.11
3. Beta Cha- an apparent visual magnitude of 4.24
4. Theta Cha– an apparent visual magnitude of 4.34
5. Delta 2 Cha – an apparent visual magnitude of 4.42
6. Epsilon Cha– an apparent visual magnitude of 4.88
7. Kappa Cha – an apparent visual magnitude of 5.02
8. Zeta Cha – an apparent visual magnitude of 5.07
Hipparcos created the apparent magnitude system to rank the brightness of Stars (for example he decided that that the grade of a first magnitude star should be twice as bright as a second magnitude Star, and so on.
FACT: The commonly quoted ‘Hipparcos Satellite’ is an abbreviation of ‘The High Precision Parallax Collecting Satellite’, which is an astrometric satellite used by the European Space Agency (ESA)
The importance of the Constellations such as Indus dates way back to the times of the Babylonians who identified constellations with bright Stars
The Bright Stars of Chamaeleon
If you look up and into the Southern night sky you can imagine the recognizable outline of the Constellation of Chamaeleon, which is imagined as a chameleon.
This main constellation is made up of 19 bright Stars.
Stars with Planets
Chamaeleon has 3 Stars with an exoplanet orbiting around it in the solar system but they are unlikely to be able to support life forms.
The three exoplanets within the Constellation, but not part of the outline, are:
- CT Cha
- HD 63454
The furthest exoplanet discovered was actually in the Andromeda Galaxy, not in the Milky Way.
Not all the stars within the Chamaeleon Constellation are visible to the naked eye but with a large telescope and other modern imagery techniques is it possible to glimpse all of the stars.
FACT: An exoplanet (also referred to as an extrasolar Planet) is a planet that orbits a Star that is not located within our Solar System (exoplanets do not orbit our Sun)
Nothing stands still in the sky.
Planets are continually being discovered and lists updated.
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.
What is the purpose of Chamaeleon –
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 Chamaeleon celestial pole
The celestial pole defines the poles of the celestial equatorial coordinate system.
An object at the Celestial pole has a declination of 0 degrees.
- The declinations for the north celestial pole is +90 degrees
- The declinations for the south celestial pole is -90 degrees
The celestial poles are not permanently in a fixed position against the background of the stars as everything moves in Space.
Chamaeleon is located in the Southern celestial sky at a +0 degree and -90 degrees declination, and an average 11-hours right ascension.
Navigational tools in the sky
The many Constellations in the night sky were a useful navigation tool and guide as well as the subject of legends and myths.
42 Constellations have been named after animals (like a Lizard or chameleon) and 29 named after an object.
There is usually a story behind each name from ancient myths to objects that have made a difference in the world, from beasts to characters (like Cetus and Indus).
Historical significance: surrounding Constellation of Chamaeleon
Myths and Stories
Many ancient civilizations have related the Constellations in the sky to suit their beliefs and creations itself. They have been the subject of folklore and experiences for a very long time.
Chamaeleon is not connected with any Greek or Roman myths or gods.
The Constellation of Chamaeleon was thought to be a small constellation that blended into the background of neighboring stars recounted from sea voyage observations. It was thought to resemble a long Chamaeleon that could be imagined sticking its tongue out towards its insect neighbor – the Constellation Mosca (known as the fly)
Ancient associations with the constellations
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.
For thousands of years, various cultures around the world have identified and named the constellation we know and see in the night sky as Chamaeleon.
The Mesopotamian civilization (the first known civilization) identified constellations like Chamaeleon
FACT: The ancient lands of the Mesopotamians now stretches across Turkey, Syria, Iraq and Kuwait
Chamaeleon and the other constellations in the sky had a practical use.
The ancient Mesopotamians and in Asia used the orientation of the constellations to set the seasons for sowing crops and harvesting.
The Babylonians also recorded details of various bright stars within the constellations in their Babylonian star catalogues before 100BCE.
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.
The meteor showers of Chamaeleon
There is only one little known meteor shower associated with the Constellation of Chamaeleon.
- Delta Chamaeleontids
It occurs within the boundaries of the Constellation of Chamaeleon with its peak around the 14th February. It occurs from deep in the Southern Hemisphere at a right ascension of 208.3 and a declination of -78.2
Fun Facts about Constellations – Did you know that?
- The Constellation of Chamaeleon is not one of the 12 constellations of the Zodiac, that appear when the Sun sets
- Constellations have been represented in many cultures as signs and navigational guides.
- The symbol of animals, formed by the position of notable stars, is associated with the Constellation of Chamaeleon and also Constellations such as Scorpius and Capricornus.
- As the Chamaeleon Constellation is made up of Stars that are in many different locations and vast distances from each other it is now possible to go to just one location to view it. It is visible from many different locations.
- The average distance to the main Stars in the small Southern Constellation Chamaeleon is around 282 light years away. As this Constellation is made up of a range of stars in different locations and distances away it is not possible to go to just one specific location to see it.
- There are over 4000 known exoplanets in the night sky, with another 5000 awaiting classification. Chamaeleon has 3 orbiting exoplanets.
- The scale of a Constellation is measured in square degrees
- The planet Jupiter is often cited when making size comparisons between planets or stars. The Jupiter mass is a unit of mass equal to the total mass of planet Jupiter
- Charles Messier the French Astronomer, who cataloged the Messier objects, has a crater on the Moon named after him.
- Constellations like Chamaeleon are not part of our Solar System; they are groups of stars that appear to form shapes that are visible with the naked eye from Earth.
- The largest Constellation is called Hydra and the smallest Constellation is called Crux
- The center of a Galaxy does not contain a Giant Star it contains a Supermassive Black Hole.
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’s the difference between a Constellation and an asterism?
A. The stars that make up a Constellation have a definite position and form, whereas an asterism is a collection of stars without a fixed position
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.
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.