South Carolina Journey to the Center of Orion

[Steve_E]

The Great Orion Nebula(M42) is arguably the most photographed deep-sky object in the night sky. It's visible to the naked eye under moderately dark skies and can be a very nice view with binoculars. Don't expect colors like seen here, because our eyes are built primarily for daylight and lack the sensitivity needed at such low light levels. It'll appear as a greenish/grey glow in binos or a telescope. Long, multiple exposures reveal incredible structure within this massive object. This huge star nursery is 1,500 light years from earth. M42 is an enormous cloud of gas(mainly Hydrogen) surrounding a group of extremely hot young stars(no not from Hollywood).

The core of this nebula is referred to as the Trapezium which is responsible for providing the heat that excites the hydrogen gas to create the glow that makes this object so spectacular. When you look at a neon light, you are seeing the same principle at work that is seen in a hyrdrogen-rich nebula. A heat source inside the neon tube causes the hydrogen gas inside to glow.

The first image below is a four-frame mosaic of a large portion of M42. I shot the object on 4 separate nights and then combined each quadrant to make the single image. Each quadrant is 2 1/2 hours of total exposure time.

The second image is a closer look at the Trapezium or core of M42(located just to the right of center). This is the heat source that lights things up. It requires a combination of different exposure lengths to reveal this region in detail. In order to preserve detail in this very bright area it's necessary to shoot both long and short exposures and strip in the shorter exposure time in the bright center so it isn't blown out. The circular shape seen at the left is M43.