Astronomy:88 modern constellations
In contemporary astronomy, the sky is divided into 88 regions called constellations, generally based on the asterisms (which are also called "constellations") of Greek and Roman mythology. The number of 88, along with the contemporary scientific notion of "constellation", was conventioned in 1922 by the International Astronomical Union in order to establish a universal pattern for professional astronomers, who defined constellations from then on as regions of the sky separated by arcs of right ascensions and declinations and grouped by asterisms of their historically most important stars, which cover the entire celestial sphere.[1] The constellations along the ecliptic are called the zodiac. The ancient Sumerians, and later the Greeks (as recorded by Ptolemy), established most of the northern constellations in international use today. When explorers mapped the stars of the southern skies, European and American astronomers proposed new constellations for that region, as well as ones to fill gaps between the traditional constellations. Not all of these proposals caught on, but in 1922, the International Astronomical Union (IAU) adopted the modern list of 88 constellations.[2] After this, Eugène Joseph Delporte drew up precise boundaries for each constellation,[2] so that every point in the sky belonged to exactly one constellation.
History
Some constellations are no longer recognized by the International Astronomical Union, but may appear in older star charts and other references. Most notable is Argo Navis, which was one of Ptolemy's original 48 constellations.
Modern constellations
The 88 constellations depict 42 animals, 29 inanimate objects and 17 humans or mythological characters.
Abbreviations
Each of the IAU constellations has an official 3 letter abbreviation. They are actually abbreviations of the genitive form of the constellation names, so some letters appearing in the abbreviation may come from the genitive form without appearing in the base name (as in Sge for Sagitta/Sagittae, to avoid confusion with Sagittarius, abbreviated Sgr).
The majority of the abbreviations are just the first three letters of the constellation, with the first character capitalised: Ori for Orion, Ara for Ara/Arae, Com for Coma Berenices. In cases where this would not unambiguously identify the constellation, or where the name and its genitive differ in the first three letters, other letters beyond the initial three are used: Aps for Apus/Apodis, CrA for Corona Australis, CrB for Corona Borealis, Crv for Corvus. (Crater is abbreviated Crt to prevent confusion with CrA.)
When letters are taken from the second word of a two-word name, the first letter from the second word is capitalised: CMa for Canis Major, CMi for Canis Minor.
The abbreviations are unambiguous, with two exceptions. Leo for the constellation Leo could be mistaken for Leo Minor (abbreviated LMi), and Tri for Triangulum could be mistaken for Triangulum Australe (abbreviated TrA).[3]
List
For help with the literary English pronunciations, see the pronunciation key. There is considerable diversity in how Latinate names are pronounced in English. For traditions closer to the original, see Latin spelling and pronunciation.
Asterisms
Various other unofficial patterns exist alongside the constellations. These are known as "asterisms". Examples include the Big Dipper/Plough and the Northern Cross. Some ancient asterisms, for example Coma Berenices, Serpens, and portions of Argo Navis, are now officially constellations.
See also
- Constellations listed by Ptolemy
- Constellations listed by Petrus Plancius
- Constellations listed by Lacaille
- List of constellations by area
- List of constellations in different languages
- Biblical names of stars
- Lists of stars by constellation
- Constellation family
- Galactic quadrant
- Zodiac
References
- ↑ Eugène Delporte; International Astronomical Union (1930). Délimitation scientifique des constellations. At the University press. https://books.google.com/books?id=v3XvAAAAMAAJ.
- ↑ 2.0 2.1 2.2 "The Constellations". International Astronomical Union. http://www.iau.org/public/themes/constellations/. Retrieved 9 December 2015.
- ↑ Russell, Henry Norris (1922). "The New International Symbols for the Constellations". Popular Astronomy 30: 469. Bibcode: 1922PA.....30..469R.
- ↑ NASA Dictionary of terms for Aerospace Use - table V, Constellations
- ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21 5.22 5.23 5.24 5.25 5.26 5.27 5.28 5.29 5.30 5.31 5.32 5.33 5.34 5.35 5.36 5.37 5.38 5.39 5.40 5.41 5.42 5.43 5.44 5.45 5.46 5.47 5.48 5.49 5.50 5.51 5.52 5.53 5.54 5.55 5.56 5.57 OED, 2nd edition
- ↑ 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12 6.13 6.14 6.15 6.16 6.17 6.18 6.19 6.20 6.21 6.22 6.23 6.24 6.25 6.26 6.27 6.28 6.29 6.30 6.31 6.32 6.33 6.34 6.35 6.36 6.37 6.38 6.39 6.40 6.41 6.42 6.43 6.44 6.45 6.46 6.47 6.48 6.49 6.50 6.51 6.52 6.53 6.54 6.55 6.56 6.57 6.58 Random House Dictionary
- ↑ The constellations Camelopardalis, Columba, and Monoceros, formed by Petrus Plancius in 1592 and in 1613, are often erroneously attributed to Jacob Bartsch and Augustin Royer
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 "Naming Stars". IAU.org. https://www.iau.org/public/themes/naming_stars/. Retrieved 30 July 2018.
- ↑ Corona Australis is sometimes called "Corona Austrina" /ɔːˈstriːnə/ (genitive: Coronae Austrinae)
- ↑ "Definition of dorado". Collins English Dictionary. http://www.collinsdictionary.com/dictionary/english/dorado. Retrieved 28 November 2012.
- ↑ Serpens may be divided into Serpens Cauda (serpent's tail) and Serpens Caput (serpent's head)
External links
- http://www.ianridpath.com/constellations1.htm – Ian Ridpath's list of constellations.
- http://www.ianridpath.com/startales/contents.htm – Ian Ridpath's Star Tales.
- http://cdsarc.u-strasbg.fr/viz-bin/Cat?cat=VI/49 – CDS's archive of constellation boundaries. The text file constbnd.dat gives the 1875.0 coordinates of the vertices of the constellation regions, together with the constellations adjacent to each boundary segment.