Orion is one of the 48 ancient constellations recorded by Ptolemy.
Historical Map of Orion
The more or less horizontal diagonal passing just above the belt of Orion is the Celestial Equator. The horizontal shaded bands at the top represent the southern portion of the zodiac, which is centered on the Ecliptic. The Ecliptic itself is shown by alternating light and dark bands, each of which represents one degree of longitude. The more or less vertical diagonal to the left of Orion is the 6-hour circle, or Solstitial Colure. Its intersection with the Ecliptic is the Summer Solstice. The Ecliptic has the same position now that it had in 1603, but the grid of right ascension and declination has shifted since then; so the Solstitial Colure, which was well to the left of Betelgeuse (Orion's left shoulder, as drawn by Bayer) in 1603, is now much closer to Betelgeuse, as shown in the modern map, below.
From Bayer's 1603 Uranometria (Image from the USNO copy of the 1661 edition of Bayer's Uranometria)
Modern Map of Orion
Modified version of Wikimedia Commons map by Torsten Bronger
Constellations Bordering Orion
(to be added in the next iteration of this page)
Stars in Orion
Stars that have common names often have multiple names, so the common names shown (if any) cannot be considered authoritative. Right ascension and declination are given in 2000.0 coordinates.
α Ori (Betelgeuse)
β Ori (Rigel)
γ Ori (Bellatrix)
δ Ori (Mintaka)
ε Ori (Alnilam)
ζ Ori (Alnitak)
Objects of Interest
|