[1] The belt consists of three bright and easily identifiable collinear star systems – Alnitak, Alnilam, and Mintaka – nearly equally spaced in a line, spanning an angular size of ~140′ (2.3°).
[2] Owing to the high surface temperatures of their constituent stars, the intense light emitted is blue-white in color.
The discredited archeological Orion correlation theory postulated a connection between the positions of the Giza pyramids and those of the belt, with the linkage shown to be spurious when placed within the proper historical context.
All three were once known as Al Niṭhām (النظام) meaning "string of pearls" with spelling variants that include Alnihan and Ainilam,[8] which was suggested by Knobel to be mistakes in transliteration or copy errors.
[9] Alnitak (ζ Orionis) is a triple star system at the eastern end of Orion's belt and is 1,260 light-years from the Earth.
The innermost binary has a period of 5.732 days and a semi-major axis of approximately 32 million kilometers (0.22 AU), with the two massive stars eclipsing each other twice per completed orbit as viewed from Sol, from which regular minor dips in brightness arise.
[16] Tennyson's poem The Princess describes Orion's belt as:...those three stars of the airy Giant's zone,That glitter burnished by the frosty dark.
[17] In China's Classic of Poetry, the asterism, under the name "Shen" (参), was paired with Antares, which is known as "Shang" (商), to be a metaphor for two people who could never unite.
[citation needed] The Malay people refer to the Orion Belt as Bintang Tiga Beradik (literally "three brother stars").
[citation needed] They also mark the northern night sky when the Sun is at its lowest point, and were a clear marker for ancient timekeeping.