|Apparent size:||85 x 60 arc min|
|Diameter:||34.7 light years.|
|Distance:||1,400 light years.|
Finally the clouds cleared – after 34 days! I got three beautiful clear nights in a row outside with my telescope! This is my “annual” image of M42, each time trying to improve on the last. It is undoubtedly one of the best nebulae in the sky, second only perhaps to the Eta Carina Nebula.
M42 is a gaseous emission nebula, which means that rather than merely reflecting starlight, the gas is illuminated due to their atoms being excited by ultra-violet light from hot new-born stars within the nebula.
The bright comma shaped object at the top of the nebula actually has it’s own classification: M43. The fuzzy patch at the top edge of the image is the Running Man Nebula, to be featured here on Cosmic Focus soon.
|Feature image date:||2021-01-09.|
|Exposure:||88 frames @ 63.8 seconds each = 94½ minutes.|
|Field of view:||1.57° x 1.04° deg. Up is 326° E of N.|
The brightest part of the nebula contains a tiny group of four very young stars, known as the Trapezium. It this region which makes M42 difficult to image, because cranking up the exposure to get the faint wispy streams of gas tends to grossly over-expose the bright region.
The following is an image of the four Trapezium stars, which I took with a Schmidt-Cassegrain telescope ten years ago. That bright over-exposed region in the feature image above is shown here much enlarged, horizontally inverted and light blue instead of white:
Here’s where M42 is located in the sky, using images generated for me by Astrometry.net:
You can spot the Orion Nebula very easily with the naked eye – and even better with binoculars or camera. You won’t see the colour without a camera. It’s just above Orion’s Belt in the Southern Hemisphere, (below it in the Northern Hemisphere):
|SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.|
|Field flattener; no filter.|
|SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.|
|Imaging camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx).|
|Software: EQMOD, PHD2, SharpCap, Gimp.|
|Observatory location: 34° South.|
Images © Roger Powell
I’m a founder member of Macarthur Astronomical Society