The Amazing Orion Nebula

My Australian nights are proving to be frequently and thankfully clear enough that I’ve got the luxury of shooting some familiar “home sky” objects. This is the famous Orion Nebula in the Sword of Orion, about 1500 light years away.

I’ve shot this nebula many times from the northern hemisphere but my Australian skies are darker than at home, and the nights a lot warmer than when this object is up in our winter sky.

The Orion Nebula is a complex consisting of Messier 42, the main nebula, M43, a small nebula attached to the north (above) and the bluish Running Man Nebula (can you see his dark figure?) at top that is officially catalogued as NGC 1973-5-7. Together, these make up the largest region of star formation in our corner of the Milky Way. It’s easy to see with the unaided eye on a dark night.

To shoot this, I blended three different exposures, short (4 x 1 minute), medium (4 x 5 minutes) and long (4 x 15 minutes), to preserve all the details from the intensely bright core our to the faint tendrils extending into deep space. I stacked the 4 frames taken at each of the exposure times, then blended those stacks using masks in Photoshop CS6 (and its wonderful and editable Refine Mask function) to mask out the overexposed area of the longer exposure and let the shorter exposure content shine through. The result is that the core still shows the little cluster of stars, the Trapezium, and the characteristic green tint of the core. But I applied lots of Curves to bring out the fainter bits and swirls in the periphery.

I shot this through my Astro-Physics Traveler 105mm refractor at f/5.8 using the filter-modified Canon 5D MkII camera, at ISO 400. This turned out to be certainly my best shot of Orion yet in my library.

– Alan, December 13, 2012 / © 2012 Alan Dyer