3.2 KiB
| name | created_by | created_date | updated_by | updated_date |
|---|---|---|---|---|
| Orion | skybber | 2021-07-11 10:20:58.966916 | skybber | 2021-07-11 10:20:58.967259 |
Orion is the jewel of our winter sky and of all the constellations it is the most prominent, impossible to miss. The basic outline of the constellation is made up of seven stars. The striking line of three 2mag stars touching the celestial equator is the belt of Orion, lying in the central part of the constellation and peaking during late winter evenings and during the cold January. The stars of the belt are called Mintaka, Alnilam and Alnitak. Between them are a handful of 5-8mag stars, collectively referred to as Collinder 70. Orion's right arm is marked by the star Betelgeuse, the left by Bellatrix. Rigel is located in the right knee, Saiph in the left. Below the belt hangs a sword formed by a line of three stars. Around the star θ Orionis, which is a wide double star discernible in triads and whose western companion θ1 Orionis is a known multiple star of the Trapezium system, the Great Nebula in Orion (M42) is visible to the naked eye. Above the Betelgeuse-Rigel conjunction lies a triangle of three stars that represents the head of the hunter. On the left side the arc of fainter stars resembles a club, on the right a hunter's shield.
Orion extends on both sides of the equator, so it is visible in its entirety except for areas close to the poles from most viewing points on Earth. The constellation offers a wide and rich collection of cosmic attractions, whether for telescopes or small triers. The main exhibit is the Great Nebula in Orion, considered by many to be the most beautiful diffuse nebula in the sky and one of the most beautiful objects visible in binoculars. Many other nebulae can be seen in the infinitely large complex of gas and dust that covers most of Orion. The entire region is interspersed with the interstellar medium and is thought to be the birthplace of stars. Many of the double, triple and multiple systems are mostly blue-white in color because they are young stars that have only recently been born in the Orion complex.
In the northern part of the constellation, the two branches of the Milky Way from Gemini and Taurus merge, and further out the Milky Way begins to gradually expand. On the eastern side it reaches almost to Procyon of the Little Dog in lateral view, while the western edge passes by the star Betelgeuse and is slightly more contrasted. Slightly to the northwest, the sparse open cluster Collinder 69 is visible to the naked eye, giving a hazy impression. It features a striking triangle of brighter stars λ (3mag), π1 and π2 Orionis (4mag). According to some observers, a large emission nebula, Sharpless 2-264, is visible to the naked eye in the very dark sky around them. This is surrounded by a ring about seven degrees in diameter consisting of a system of dark nebulae. It is no coincidence that it is therefore nicknamed, especially in photographs, the Ring around λ Orionis. But the truth lies somewhere in the middle. The nebula itself is covered by a mass of indistinguishable stars far beyond the limit of visibility, and the surrounding dark nebulae bordering the star cloud only give the impression of an artificial ring.
