There are 88 modern recognized by the International Astronomical Union (IAU). The list of the modern was adopted by the IAU in 1922.
The constellation boundaries as we know them today were set in the late 1920s. 36 modern lie principally in the northern celestial hemisphere, while 52 are found in the southern sky.
The list of the modern and the abbreviations used for them were produced by American astronomer Henry Norris Russell and approved by the IAU in May 1922.
Russell’s list corresponded to the listed in the Revised Harvard Photometry star catalogue, published by Harvard College Observatory in 1908.
The constellation boundaries were drawn by Belgian astronomer Eugène Delporte and officially adopted in 1928.
Who created the constellations?
The 88 modern have different origins.
Most of them are roughly based on the 48 ancient catalogued by the Greek astronomer Claudius Ptolemy of Alexandria in his Almagest.
an ancient astronomical treatise written in the 2nd century CE.
These are mostly associated with figures from Greek mythology.
They include Andromeda, Cassiopeia, Perseus, Pegasus, Hercules, Orion, Ursa Major, Ursa Minor, Canis Major, Canis Minor, Eridanus, and the 12 zodiac .
However, Ptolemy did not create these
They were already well-known to observers long before his time. Even though they are called Greek , they were not necessarily created by the Greeks.
Depictions of some of the ancient constellations or the asterisms they are known for go back to prehistoric times and their creators are unknown.
Fifty of the modern 88 constellations are based on the Greek ones.
Only one of Ptolemy’s constellations – Argo Navis – is no longer in use.
It was divided into three smaller constellations – Carina, Puppis and Vela – by the French astronomer Nicolas-Louis de Lacaille in the 18th century.
The three smaller constellations remain in use.
Constellation Guide
The International Astronomical Union recognizes 88 constellations covering the entire northern and southern sky.
Here is a selection of the most familiar and easily seen constellations in the northern sky.
A constellation is formally defined as a region of the celestial sphere with boundaries laid down by the International Astronomical Union (IAU).
Constellations are usually based on asterisms, which are chance groupings of stars in the sky that resemble familiar patterns.
Some constellations contain other asterisms within them. For example, the Big Dipper is an asterism located within the constellation Ursa Major.
The constellations are actually much larger than the asterisms they contain.
Today there are a total of 88 constellations that cover the entire night sky.
36 of these are located in the northen hemisphere of the sky while the remaining 52 are in the southern hemisphere.