The famous Great Orion Nebula (NGC 1976, M42) is a favourite of astronomers, both observers and
photographers, being a bright, easily located object, that can be appreciated even through binoculars.
It is the bright “middle star” of Orion’s Sword (or, in our Southern Hemisphere skies, it is the "middle
star" of the Saucepan's handle).

NGC 1976 is a large, diffuse emission nebula that is the closest known massive star-forming region
to us in our galaxy. It lies just 1344ly away and is estimated to be 24ly across, making it appear 2x
diameter of the Moon. Being so close, professional astronomers have studied it intensely in an effort
to understand the processes of star formation.

The centre of the bright region in the nebula is dominated by an open cluster of very young, hot stars,
known as the “Trapezium” after the four very bright foreground members, easily visible in modest
telescopes. The open cluster is an association of an estimated 2,800 stars, mostly obscured by the
bright nebula surrounding it. In fact, it is the UV light emitted by this cluster that ionizes the gas in the
nebula, making it glow so prominently. The Orion Nebula lies within a much larger structure known
as the Orion Molecular Cloud Complex which extends across much of the Orion constellation.

Note: This is a difficult target in that it has a huge brightness range (high-dynamic range). Because of
this, I made two series of exposures, one of just 10sec to capture the bright nebula at the centre with
its embedded "Trapezium", and the other of 180sec to capture the remainder of the nebula. I combined
these using Pixinsight's HDRCombination tool.


Telescope: Askar PHQ107 refractor, f=750mm
Camera:    ZWO ASI294MC Pro
Exposure: 23 x 180 sec + 30 x 10sec, gain = 125, no filter
                  Bortle 3-4 sky, 30% Moon waning
Field of View: approx. 1º 15’ x 0º 53’
Image processed and prepared in PixInsight and Photoshop Elements