Do you know what the Austral constellations are?
Southern Constellations they are a category within all constellations discovered so far. They refer to the set of constellations that can be observed from the southern hemisphere of the Earth.
With the southern hemisphere we mean any point on the planet located from the line of Ecuador downwards. However, these can be seen much better at observation points further south, such as Antarctica, Argentina, New Zealand and South Africa.
The Atacames desert in Chile is one of the best southern astronomical observation points due to the absence of lights.
Have you ever wondered if there is life outside our planet? Don't miss our article on the Earth-like planets!
Some of the southern constellations are very famous, especially the zodiacal ones such as: Scorpio, Pisces Sagittarius, Libra and Aquarius. Also other very famous ones like Orion and Centaur.
But, those are not all. In fact, there are many, many stellar groups enclosed within this category.
How many Austral constellations are there?
Since its constitution in 1928, The International Astronomical Union (IAU) has identified and endorsed a total of 88 constellations observable from the earth, of which 40 are considered Austral Constellations.
To do this, they had to corroborate hundreds of constellations discovered by hundreds of astronomers throughout history, even thousands of years ago by different cultures (Greeks, Egyptians, Persians, etc.)
This turned out to be a long process, since various cultures identified the same constellations with different names.
On the other hand, they had to clearly delimit the borders between one constellation and another, avoiding overlapping and confusion. This process obliterated hundreds of minor stellar constellations such as Cerberus, Gallus, and Cancer Minor.
What is the difference between the Boreal and Austral Constellations?
The difference between the two constellations is very simple and has to do with the point on our planet from which each group of constellations is observable.
Boreal Constellations they are observed from the northern hemisphere of the planet, especially from the Arctic and countries with a very northern location, such as Alaska (USA), Iceland and Ireland.
Meanwhile, the Southern Constellations They are the ones that can be observed from the southern hemisphere. The main astronomical observatories that can capture them are in Atacames (Chile), New Zealand and South Africa.
However, some constellations are so bright that they don't require a telescope and can be located with the naked eye on a clear night. Also, for more information on how to view them, you can check out our article on constellations and how to see them.
What are the Austral Constellations
We have mentioned that so far, the IAU has cataloged 40 Southern Constellations, which are the main ones?
Female Hydra:
Hidra It is the largest of the 88 constellations currently recorded, with an area of 1303 square degrees when viewed from Earth and is made up of an amazing group of 238 stars.
Hydra (Hya, for short) was discovered and recorded by Ptolemy, making it one of the oldest recorded constellations today.
Hydra is made up of several high-luminosity giant stars, making it very easy to locate, even with an amateur telescope.
alphard o Cor Hydrae is the brightest star in this constellation.
It is a luminous orange giant star, with almost 60 times the radius of our sun and 900 times the luminous power. It is located at a distance of approximately 179 light years from our planet.
You can locate Hydra just under the constellation of Cancer and its “tail” (the lowest point) will help you find Centaurus y Pound.
Hydra, like all the Ptolemaic Constellations, receives its name from a Greek mythological creature; in this case the Hydra of Lerna, a sea serpent that Hercules had to kill in the second of his 12 missions, imposed by the Oracle of Delphi to exculpate him for the murder of his wife and children.
Phoenix
Phoenix is a relatively small Southern Constellation, which can be easily seen from South Africa and New Zealand.
First recorded in the XNUMXth century by the German astronomer Petros Plancios. It was later reaffirmed by Frederick De Houtman and included in the book "Uranometry" by Johan Bayer in 1603.
Phoenix is the most important of the family of constellations recorded by Plancios, it is also the largest in extension of this group, with a measurable area of 463 square degrees.
Phoenix It is made up of a total of thirty stars (so it is considered a medium constellation), of which, its brightest star is Nair-al-Zaurak, an orange subgiant that is 62 times brighter than our sun, despite only having 2.5 times its mass.
Nair al-Zaurak is so bright that it can be seen with the naked eye in a clear night sky. Also, if you want to learn more about the constellations, you can read our article on constellations and galaxies.
This group was named after the mythological bird that, according to Greek, Persian and Chinese mythologies, is reborn from its ashes after completing its life cycle.
In its record account, it is said that the name was chosen because the star formation resembles the shape of a newborn bird.
Centaurus
Centaurus is one of the best known southern constellations. In fact, it is a constellation with stars very close to our solar system, including Alpha Centauri, the closest star to our sun, only 4.2 light-years away.
This constellation is a member of the family of Ptolemaic constellations, recorded during the XNUMXnd century by the noted Greek astrologer, Ptolemy.
Another notable feature of the Centaurus constellation is its size, at 1060.4 square degrees across, which makes it the ninth largest constellation registered by the UAI
On the other hand, it is made up of a total of 281 stars (more than Hydra). Alfa Centauri is also its brightest star despite being a spectral class red dwarf.
This occurs due to its very high electromagnetic activity, which produces very powerful unpredictable flashes of light, which can last a few minutes or several weeks.
His name is inspired by the Centaur of Greek mythology. A hybrid being, with horse legs and a human torso, known for ignoring human laws.
However, the constellation was named after Chirion, the heroic centaur who fought alongside Hercules against the Hydra of Lerna and died from a poisoned arrow.
May is the best month to see Centaurus, especially during the meteor showers associated with this constellation. You can learn more about this star's distance in our article on the distance to Alpha Centauri.
Crux
cross or The Cross is a small constellation in the southern celestial hemisphere, with a sky extension of only 68.4 square degrees but formed by a group of 49 stars. Crux is the smallest constellation of the 88 cataloged today.
It is very easy to locate in the night sky, mainly because of its simple shape and because it is right next to the bottom of Centaur.
The Crux star formation is shaped precisely like a cross, forming two crossed straight lines when the horizontal and vertical points of the 49 stars that make up the constellation are joined.
This constellation was known to observers in Persia, Jerusalem, and Mesopotamia during the XNUMXnd and XNUMXrd centuries. In fact, the first Christians related these stars to the birth of Jesus of Nazareth.
The ancient Greeks considered it to be an extension of Centaurus (since it borders it on three different sides). It was not until the XNUMXth century that Petrus Plancius included it as an independent constellation with the name it currently bears.
Its brightest star is B Crux (or Mimosa), a spectral blue subgiant star located 280 light years from our solar system.
A curious fact about Crux is that it was also an important constellation for the Inca people, who knew it as Chakana. Its symbology in pre-Columbian mythology represented the union between the earthly world and the world of the gods.
southern fish
The constellation Pez del Sur is also known as Pisces Austrinus, which should not be confused with Pisces, the zodiacal constellation.
The Southern Fish is one of the oldest constellations preserved by the IAU today. It was discovered and introduced by the Greek astronomer Ptolemy during the second century.
The Greeks believed that this constellation was shaped like a fish, but not just any fish. Piscis Austrinus was named in honor of Right, the fish that saved Atargatis, the Syrian goddess of fertility, from drowning in a river. You can also read more about the characteristics of the constellations in our article on .
puppies
Puppis is more commonly known as the South Popa constellation. This star formation is one of the three small constellations resulting after dividing Argo ship.
Nave Argo was the huge constellation that ruled the southern sky in ancient times (more than 1800 square degrees in extent) and was discovered by Ptolemy, but dismissed in the XNUMXth century by Louis de Lacaille, resulting in four small minor modern constellations: Puppis (the stern), Carina (The Keel), and Vela (the Sail) and Pyxis (Compass).
South Popa is the largest of the four resulting constellations. It is ruled by Naos, its brightest star. A blue supergiant star much larger (more than 30 times) and brighter than our own Sun.
Naos is so bright that you can easily see them from anywhere in the southern hemisphere without a telescope.
Sailing
Vela is another small constellation in the night sky, resulting from the separation of Nave Argo.
The Vela Constellation would really fall into the "median" category as it has a visible extent of 499.6 degrees. It is made up of a total of 214 stars, many of them visible without a telescope.
Its brightest star is Gamma Velorum, which is actually an entire solar system, made up of 7 stars of great size and luminosity (those discovered so far).
The brightest component of Gamma Velorum is Gamma Velorum A, a super hot binary star, about 70.000 Kelvin (Our Sun is only 5.000 K). Gamma is believed to Verlorum A is a dying star and the candidate for Closest supernova to our solar system.
fornax
Fornax Chemical It is also known as The Chemical Furnace Constellation. It was introduced by the French astronomer Nicolas-Louis de Lacaille, who was responsible for recording and cataloging more than 10.000 stars in the XNUMXth century.
His observations and corrections were of vital importance to achieve the current classification of the 88 constellations in force today.
Fornax is not a really massive constellation, since it only measures 397,5 square degrees and is made up of 59 stars, almost all of which have very low luminosity.
Although not very large, Fornax's deep sky contains the Fornax Cluster, a concentration of galaxies, one of the most populous clusters of galaxies discovered to date. This formation is only 62 light years from our system.
It borders other very large southern constellations and can be found between Cetus and Phoenix, mainly during the month of December.
Cetus
The constellation Cetus has a much more popular name: The Whale. Cetus is the most imposing of all the constellations in the region of the southern sky known as Water Region.
The Whale can be easily seen together with other southern "marine" constellations such as Pisces, Aquarius and Eridanus. It also abuts lower Aries.
Cetus is a huge constellation, with a total area of 1231 square degrees, making it one of the largest of the 88 currently in existence.
It can be seen completely with the naked eye in the clear night sky, practically from anywhere in the world since it is located in the equatorial zone of the sky, especially during the month of September.
Cetus is made up of an approximate number of 189 stars. Its brightest star is Deneb Kaitos, a giant orange sun, somewhat distant from our solar system. Despite the distance of 96 light-years, Deneb Kaitos is very bright because of its strong surrounding magnetic field.
Deneb Kaitos represents the tip of the Whale's head, which faces north, and Menkar, another of its brightest stars, marks the tail, which is pointing south.
The data on the discovery and registration of Cetus can be somewhat confusing because it has been known since ancient times. However, it was most likely introduced by the Persians just over 2000 years ago.
Do you know what the Austral Triangle is?
The Southern Triangle is one of the most emblematic constellations in the southern hemisphere, despite also being one of the smallest.
It has only 110 square degrees of extension and is made up of a total of 35 stars, although it can be delimited using only 3.
The Austral Triangle should not be confused with the Triangulum, another southern constellation.
This formation of stars describes a perfectly defined equilateral triangle, delimiting its angles with its three brightest stars: Alpha Triangulis, Beta Triangulis and Gamma Triangulis.
Its brightest star is Atria. An orange giant star with a luminous output very close to that of our sun, around 4400 K, despite having a solar radius 130 times larger.
It is a relatively new constellation, first introduced thanks to Frederick de Houtman's observations in the 21th century. The best month to observe this constellation is in July, around 00:XNUMX p.m.
Other Austral Constellations
antlia
A small, low-brightness star constellation that is not easy to see in the sky with the naked eye. A landmark to find it is Hydra's tail; it also borders Centauro to the west.
columba
Also known as: The Dove. Columba is a small constellation of 68 stars arranged in a straight line. Can be found during February east of Puppis.
crown australis
The Southern Crown constellation is part of the family of ancient Ptolemaic constellations. Its shape describes a semi-curve opening to the east and is bordered to the north by Sagittarius.
Eridanus
Eridanus is part of the so-called water region constellations. It is actually a very large star formation, with 200 components and an extent of more than 1000 square degrees. It ranks 6th in magnitude of the 88 constellations.
Eridanus represents a river, which seemed to flow alongside the waters of Aquarius (both constellations are almost united).
The Greek myth of this constellation relates it to Phaethon, the demigod who stole Helios' sun chariot, but lost control, crashing to earth and burning the skin of humans.
