Introduction
The world humanity is living in is not limited by Earth, which is, actually, only one of the multiple objects the Universe comprises. Even without knowing the origin of celestial objects, people have observed them for thousands of years and tried to organize what they saw into understandable outlines. Nowadays, the patterns those outlines form are referred to as constellations, and it seems as if they have been on the sky forever. Furthermore, human intelligence has made it possible to explore the space and identify the laws and algorithms its functioning obeys to, for which reason there is no more need for symbolic descriptions. The modern science describes and studies constellations based on their physical and astronomical qualities, which is the responsibility of the International Astronomical Union.
History of the Constellations
One would probably describe a constellation as a group of stars, but that is apparently not quite accurate. According to the Oxford English Dictionary, the stars have to form “a recognizable pattern […] traditionally named after its apparent form or identified with a mythological figure” (Lexico). The critical point is that the key criterion for identifying a group of stars as a constellation is the shape observable from the Earth.
Throughout the history, the objects people saw in the sky have played a considerable role in their attempts to explore the outside world and live in harmony with it. Therefore, many of the constellations that are determined today have some mythological background. Thus, the Big Dipper and the Little Dipper are parts of bigger groups, Ursa Major and Ursa Minor, respectively, which means “The Big Bear” and “The Little Bear.” The latter, in turn, are named after the characters of ancient Greek myths, the nymph Callisto and her son Arcas, whom Greeks believed to have been carried into heavens by Zeus (Krithika, 2016). This is presumably the brightest example of how the ancestors sought to explain the existence of group of stars in accordance with their worldview.
Another case is that of Orion, which the humanity have also known since ancient times. Mythological hunter, the most handsome man in Greek mythology, gave his name to one of the brightest groups of stars observable from the northern hemisphere (“Orion constellation”). It would also be reasonable to mention that ancient Greeks not simply associated the celestial patterns with mythological characters or objects, but used them practically. For instance, the Sun’s circular path across the sky, which is called the ecliptic, helped to identify the season. The twelve constellations that lie along the ecliptic form the so-called zodiac family.
The titles zodiac constellations are known under also have mythological backgrounds. For instance, Taurus, which is a bull from Latin, is associated with one of the shapes Zeus could adopt (“Taurus constellation”). Gemini, which means “the twins” in Latin, represents mythological twins Castor and Pollux. All of the constellations that belong to zodiac family were first listed by Ptolemy, the ancient Greek astronomer, in the 2nd century (“Gemini constellation”). The names that the investigator assigned to the groups of stars he observed have not changed since then.
The IAU
Formation and Activity
Nowadays, constellations, similarly to all celestial objects, are in the jurisdiction of the International Astronomical Union (IAU). The organization that comprises communities and fellowships from over 100 countries around the globe was founded in Brussels in 1919 (International Astronomical Union, n.d.a). Its creation apparently was a predictable result of international cooperation in the sphere of astronomy, which, in turn, rooted at the general scientific progress of the 19rth century.
The most essential activities of the IAU include organizing scientific meetings and defining fundamental constants both in physics and astronomy. In addition, the Union “serves as the internationally recognized authority for assigning designations to celestial bodies and surface features on them” (International Astronomical Union, n.d.a). Simply put, the IAU as a member of the modern scientific community is responsible for identifying as well as labelling constellations.
Decision on Constellations
Ancient Greeks described 48 constellations in total, which equals more than a half of those the IAU recognizes today. Originally, there was no official demarcation of constellations boundaries, but it became necessary at the beginning of the 20th century, as space exploration grew faster and more intensive (International Astronomical Union, n.d.b). One of the key reasons for deciding where one group of stars ends and another begins was the discovery of so-called variable stars that brighten and pale instead of shining evenly. As such stars were named after the constellations they belonged to, it became critical to agree on separating the latter first. In 1930, Belgian astronomer Eugène Delporte catalogued the 88 constellations the IAU currently defines (International Astronomical Union, n.d.b). It is worth mentioning that the identification considers sky coordinates, not the shape visible from the Earth, as the same group of stars may have several variants of representation.
Recent Findings: 1I/’Oumuamua and 2I/Borisov
30 August 2019 is the date when an amateur astronomer from Crimea, Gennady Borisov, noticed a comet-like object with the help of his hand-built telescope. It took the IAU Minor Planet Center about a week to calculate the preliminary orbit, which allowed for identifying the object as interstellar. The discovery was epochal, as that was only the second object of such a kind to have been observed within the Solar System. The first part of the name the IAU assigned to it, 2I, is the abbreviation of “second interstellar [object]” (International Astronomical Union, n.d.c). As for the other half, the Union traditionally names comets after those who discovered them.
The finding was made no later than two years after that of the first interstellar cometary object, 1I/’Oumuamua. It was discovered by Dr. Robert Weryk from the Institute for Astronomy of the University Hawaii-manoa and did not correspond to any of the designation schemes the IAU was using (International Astronomical Union, n.d.d). Therefore, the Executive Committee of the Union decided to develop the new one, with the letter “I” meaning “interstellar.” The short interval between the two discoveries allows assuming that such objects may be numerous enough to provide a tool for a more thorough investigation of other planetary systems.
Stellar Objects in Gemini
The table below contains a brief summary on the five most known stellar objects that reside in the constellation of Gemini (“Gemini constellation”).
Conclusion
Constellations fixed groups of stars and other celestial objects that have clear outlines. Before the early 20th century, people used to associate those groups with mythological characters or other images they resembled visually. Nowadays, the boundaries of the constellations are determined based on star sky coordinates by the International Astronomical Union, the worldwide organization created in 1919. Its other responsibilities lie in organizing scientific conferences, defining fundamental constants, and exploring the space in general.
References
Gemini constellation. (n.d.).
International Astronomical Union. (n.d.a). About the IAU.
International Astronomical Union. (n.d.b). IAU and the 88 constellations.
International Astronomical Union. (n.d.c). Naming of new interstellar visitor: 2I/Borisov.
International Astronomical Union. (n.d.d). The IAU approves new type of designation for interstellar objects.
Krithika, R. (2016). Up above the world so high. The Hindu.
Orion constellation.(n.d.).
Oxford English and Spanish dictionary, synonyms, and Spanish to English translator. (n.d.). Lexico.
Taurus constellation. (n.d.).