Omicron
Omicron /ˈɒmɪkrɒn, oʊˈmaɪkrɒn/[1] (uppercase Ο, lowercase ο, literally 'small o': όμικρον < ὂ μικρόν - ò mikrón, micron meaning 'small' in contrast to omega) is the 15th letter of the Greek alphabet. In the system of Greek numerals it has a value of 70. This letter is derived from the Phoenician letter ayin
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The upper-case letter of omicron (O) was originally used in mathematics as a symbol for Big O notation (representing a function's asymptotic growth rate), but has fallen out of favor because omicron is indistinguishable from the Latin letter O and easily confused with the digit zero (0).
Omicron is used to designate the fifteenth star in a constellation group, its ordinal placement a function of both magnitude and position.[2][3] Such stars include Omicron Andromedae, Omicron Ceti, and Omicron Persei.
Character encodings
- Greek Omicron / Coptic O[4]
Preview | Ο | ο | Ⲟ | ⲟ | ||||
---|---|---|---|---|---|---|---|---|
Unicode name | GREEK CAPITAL LETTER OMICRON | GREEK SMALL LETTER OMICRON | COPTIC CAPITAL LETTER O | COPTIC SMALL LETTER O | ||||
Encodings | decimal | hex | decimal | hex | decimal | hex | decimal | hex |
Unicode | 927 | U+039F | 959 | U+03BF | 11422 | U+2C9E | 11423 | U+2C9F |
UTF-8 | 206 159 | CE 9F | 206 191 | CE BF | 226 178 158 | E2 B2 9E | 226 178 159 | E2 B2 9F |
Numeric character reference | Ο | Ο | ο | ο | Ⲟ | Ⲟ | ⲟ | ⲟ |
Named character reference | Ο | ο | ||||||
DOS Greek | 142 | 8E | 166 | A6 | ||||
DOS Greek-2 | 190 | BE | 233 | E9 | ||||
Windows 1253 | 207 | CF | 239 | EF |
- Mathematical Omicron[5]
These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.
Preview | 𝚶 | 𝛐 | 𝛰 | 𝜊 | 𝜪 | 𝝄 | ||||||
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Unicode name | MATHEMATICAL BOLD CAPITAL OMICRON | MATHEMATICAL BOLD SMALL OMICRON | MATHEMATICAL ITALIC CAPITAL OMICRON | MATHEMATICAL ITALIC SMALL OMICRON | MATHEMATICAL BOLD ITALIC CAPITAL OMICRON | MATHEMATICAL BOLD ITALIC SMALL OMICRON | ||||||
Encodings | decimal | hex | decimal | hex | decimal | hex | decimal | hex | decimal | hex | decimal | hex |
Unicode | 120502 | U+1D6B6 | 120528 | U+1D6D0 | 120560 | U+1D6F0 | 120586 | U+1D70A | 120618 | U+1D72A | 120644 | U+1D744 |
UTF-8 | 240 157 154 182 | F0 9D 9A B6 | 240 157 155 144 | F0 9D 9B 90 | 240 157 155 176 | F0 9D 9B B0 | 240 157 156 138 | F0 9D 9C 8A | 240 157 156 170 | F0 9D 9C AA | 240 157 157 132 | F0 9D 9D 84 |
UTF-16 | 55349 57014 | D835 DEB6 | 55349 57040 | D835 DED0 | 55349 57072 | D835 DEF0 | 55349 57098 | D835 DF0A | 55349 57130 | D835 DF2A | 55349 57156 | D835 DF44 |
Numeric character reference | 𝚶 | 𝚶 | 𝛐 | 𝛐 | 𝛰 | 𝛰 | 𝜊 | 𝜊 | 𝜪 | 𝜪 | 𝝄 | 𝝄 |
Preview | 𝝤 | 𝝾 | 𝞞 | 𝞸 | ||||
---|---|---|---|---|---|---|---|---|
Unicode name | MATHEMATICAL SANS-SERIF BOLD CAPITAL OMICRON | MATHEMATICAL SANS-SERIF BOLD SMALL OMICRON | MATHEMATICAL SANS-SERIF BOLD ITALIC CAPITAL OMICRON | MATHEMATICAL SANS-SERIF BOLD ITALIC SMALL OMICRON | ||||
Encodings | decimal | hex | decimal | hex | decimal | hex | decimal | hex |
Unicode | 120676 | U+1D764 | 120702 | U+1D77E | 120734 | U+1D79E | 120760 | U+1D7B8 |
UTF-8 | 240 157 157 164 | F0 9D 9D A4 | 240 157 157 190 | F0 9D 9D BE | 240 157 158 158 | F0 9D 9E 9E | 240 157 158 184 | F0 9D 9E B8 |
UTF-16 | 55349 57188 | D835 DF64 | 55349 57214 | D835 DF7E | 55349 57246 | D835 DF9E | 55349 57272 | D835 DFB8 |
Numeric character reference | 𝝤 | 𝝤 | 𝝾 | 𝝾 | 𝞞 | 𝞞 | 𝞸 | 𝞸 |
References
Look up Ο or ο in Wiktionary, the free dictionary. |
- "omicron". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public library membership required.)
- Martin, Martha Evans (1907). The Friendly Stars (1st ed.). New York: Harper & Brothers Publishers. p. 135. Retrieved 8 February 2016.
- Wilk, Stephen R. (2007). Medusa: Solving the Mystery of the Gorgon (1st ed.). New York: Oxford University Press. p. 201. ISBN 9780199887736. Retrieved 8 February 2016.
- "Greek and Coptic (Range: 0370–03FF)" (PDF). The Unicode Standard, Ver. 8.0. Unicode, Inc. 2015. Retrieved 8 February 2016.
- "Mathematical Alphanumeric Symbols (Range: 1D400–1D7FF)" (PDF). The Unicode Standard, Ver. 8.0. Unicode, Inc. 2015. Retrieved 8 February 2016.