Constellations are apparent clusters of stars which astronomers of ancient times imagined forming figures of people, animals, or objects. On a dark night, one can see between 1000 and 1500 stars, each star belonging to some constellation. Constellations help us separate the sky into smaller portions. Here some cool constellation facts to empower your brain with.
Asterisms and Constellations Facts
- Asterism is a common term heard when it comes to constellations. Asterisms are also clusters of stars but are not always constellations. An Asterism might be a part of of a constellation or might as well involve stars of two different constellations. An example of an Asterism is the “Big Dipper” or the “Plough” which is a part of the Ursa Major Constellation.
- The word constellation has its roots in the Latin term “tardio constellatio“, which can be translated as “set of stars”. A more functional definition would be a recognisable pattern of stars whose appearance is associated with mythical characters, creatures, or certain characteristics. It is also important to note that the colloquial use of the word “constellation” generally does not differentiate between an asterism and the area around it.
- Constellations existed long before there was astronomy or science. There are cave drawings showing that people have already grouped stars into pictures and figures. In fact, archaeological studies have identified marks in the famous rock paintings at Lascaux in southern France (about 17,300 years), which could be representations of the Pleiades cluster and the Orion Belt.
Constellation with Bright Stars
- One of the most famous constellation is the Orion. Orion contains two of the brightest stars in the sky, Betelgeuse and Rigel, and has a total of 81 stars. The brightest star in the Orion constellation is Rigel, and is considered the seventh brightest star in the sky.
- There are currently 88 officially recognised constellations in total, which together cover the entire sky. Therefore, any given point in a system of celestial coordinates can be unequivocally assigned to a constellation. In fact, location of constellations are often used by sea navigators to estimate their location while traveling.
- Farmers used to depend on constellations too to determine the time of the year and plan the sowing and harvesting. This was usually done in places where the changes in the weather were very subtle.
Constellations in Historical Times (Mesopotamian Era)
- Humans have long since associated with constellations. Some historical records which belong to the Mesopotamian Era (4000 B.C.E) have referred to to constellations. Constellations used in Astrology like Leo, Taurus, Gemini, Capricorn, etc were first found between 2000 – 3000 BCE by Sumerians and Babylonians.
- The constellations are divided into two groups – the northern constellations and the southern constellations. There are 15 Southern Constellations – Crater, Argo Navis, Canis Major, Lupus, Canis Minor, Centaurus, Corona Australis, Eridanus, Hydra, Corvus, Ara, Lepus, Orion Cetus, and Pisces Austrinus. The Northern Constellations are 21, namely – Draco, Cassiopeia, Ophiuchus, Triangulum, Cepheus, Pegasus, Delphinus, Perseus, Lyra, Andromeda, Aquila, Sagittarius, Cygnus, Equuleus, Hercules, Auriga, Boötes, Serpens, Corona Borealis, Ursa Major and Ursa Minor. (Constellation Facts)
- There are some shifting constellations that are visible in both northern and southern hemisphere depending on the time of year/ seasons. Orion is a famous constellation that can be seen from both the hemispheres.
Astrology and Constellations
- Astrologers have defined their own set of 12 Zodiacal Constellations namely, Aries, Aquarius, Cancer, Capricorn, Gemini, Leo, Libra, Pisces, Sagittarius, Scorpius, Taurus and Virgo. There are located within 9 degree band of each other.
- There is a 13th constellation in the zodiac that is unknown to most people. Its name is Ophiuchus the ‘serpent-bearer.’
- Most constellations are constantly shifting in the sky. However, there are some constellations that never set or rise. These constellations are known as circumpolar constellations. These are the constellations that make excellent reference points for locating seasonal constellations.
- An excellent example of circumpolar constellation is the asterism Big Dipper, that is always visible in the northern hemisphere, even during the day. Here’s how the Big Dipper looks like in different seasons.
- Ancient sea navigators used to take Polaris as a reference to estimate their location and the Little Dipper (Ursa Minor) to know their latitude.
- The largest constellation known to us is Hydra. It covers 3.16% of the sky. While Crux is the smallest constellation which covers only 0.17% of the sky. (Largest and smallest constellations)
Plotemy Recognized Most Constellations in 150 A.D.
- Out of the 88 constellations that we recognize today, 48 constellations were recorded by Ptolemy (A Greek Astronomer) in his book “Almagest” in 150 A.D. (History of Constellations)
- Constellation families consist of a number of constellations. Identified constellation families are Ursa Major Family, Zodiac Family, Perseus Family, Hercules Family, Orion Family, Heavenly Family, Bayer Family, La Caille Family. You can read more about family of constellations.
- Centaurus constellation has 101 visible stars, which is the largest number of visible stars in any galaxy.
- Sirius, the brightest star known to humans is a part of Canis Major Constellation.
- The faintest constellation know to use is Mensa.