The Orion Nebula: Star Forming Region and Splendid Winter Target

The Orion nebula, also known as Messier 42 (M-42), is one of the most splendid winter deep sky targets for amateur astronomers. It can be seen as a faint fuzzy patch for those of us with excellent vision, just below the three belt stars of the constellation Orion.

Map of Orion

In binoculars this patch of light shows some sweeping details and groups of stars surrounding the area. Through a modest telescope, the details do start to pop out, and if using a telescope of 16 or more inches in diameter, you will start to get hints of greenish color when viewing through an eyepiece.  Unfortunately, the human eye is not the most sensitive to the red light that excited Hydrogen gas gives off (656.3nm), and the Orion Nebula outs out a lot of its light at this wavelength. As a bright nebula, it has become a favorite target for budding astrophotographers: even a small telescope and short exposures of a minute or so will show some very satisfying detail. Here is a color image of M-42 taken with the school’s Takahashi FC-125, a 125mm (5″) diameter refractor. The camera was a Nikon D-810a DSLR, their version of the D-810 but without their IR blocking filter. This allows a much higher sensitivity to the Hydrogen emission lines at 656.3nm. The “a” means astronomy in Nikon lingo. This image is constructed with three separate 60 second exposures, cleaned up by removing bias, dark and flat fields, then merged together to show the bright inner details along with the fainter outer regions of the nebulosity.

Orion Nebula

The nebula itself is some 1344 light-years from our Solar System and is about 24 light-years across. It is a well studied star forming region, with some of its young stars forming protoplanetary disks, the precursors to solar systems.


A Wide Field Orion Taking on Taurus

Winter is the Orion time…. time to get a wide field camera taking snaps of the winter sky. Here is a wide field frame of Orion with his nemesis, Taurus the Bull. This was a process-image of seven 15-second exposures at f/3.5 28mm, ISO10000, with automatic dark frame subtraction using a Nikon D810a on a tracking mount. Post processing was done in PixInsight to stack the images using median combine, flatten the background, correct color, then crop and save off as a JPG with the correct histogram. Some graininess was removed in Photoshop in the end.

This shows Orion with its definitely-fading Betelgeuse (upper left shoulder), the Orion Nebula, The Barnard Loop, The Rosette Nebula, Sh2-264 (Lamda Orionis Ring) and NGC2175 (upper left).   Click on the image for full size.

Orion and Taurus Wide Field 2020-01-18

Orion and Taurus Wide Field 2020-01-18

For an annotated picture:

with titles