Orion Nebula

The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated south of Orion's Belt in the constellation of Orion. It is one of the brightest nebulae, and is visible to the naked eye in the night sky. M42 is located at a distance of 1,344 ± 20 light years and is the closest region of massive star formation to Earth. The M42 nebula is estimated to be 24 light years across. It has a mass of about 2000 times the mass of the Sun. Older texts frequently referred to the Orion Nebula as the Great Nebula in Orion or the Great Orion Nebula.

The Orion Nebula is one of the most scrutinized and photographed objects in the night sky, and is among the most intensely studied celestial features. The nebula has revealed much about the process of how stars and planetary systems are formed from collapsing clouds of gas and dust. Astronomers have directly observed protoplanetary disks, brown dwarfs, intense and turbulent motions of the gas, and the photo-ionizing effects of massive nearby stars in the nebula. There are also supersonic "bullets" of gas piercing the dense hydrogen clouds of the Orion Nebula. Each bullet is ten times the diameter of Pluto's orbit and tipped with iron atoms glowing bright blue. They were probably formed one thousand years ago from an unknown violent event.

Image Data: Orion Nebula

Lens / Scope: William Optics Megrez 102 S.V. with WO Type II 0.8x FF/FR 

Focal Length: 571.2mm 

F/stop: f/5.6 

Exposures: 

Ha: Stack of 83 420-second exposures (9h 41m total exposure)

RGB: Stack of 149 420-second exposures (17h 23m total exposure)

HDR: 

       Stack of 50 8-second exposures (6m 43s total exposure)

       Stack of 50 15-second exposures (12m 30s total exposure)

       Stack of 50 30-second exposures (25m total exposure)

       Stack of 50 60-second exposures (50m total exposure)

       Stack of 50 150-second exposures (2h 5m total exposure)

Mount: Sky-Watcher HEQ5 Pro SynScan GOTO (CdC and EQMOD Control) 

Guiding: Sky-Watcher 80 with QHY5 (PHD Control) 

Camera: Canon 500D (Digital Rebel T1i) Baader Mod (EOS Utility Control) 

Mode: RAW 

ISO: Ha – 800 ;  RGB – 400  

White Balance: Ha –  Daylight ; RGB – Custom

In-Camera Noise Reduction: Off 

Filters: Astronomik Ha 12nm ; Hutech IDAS LPS

Dates: From December 27 2011 to January 27 2012

Location: Beja, Portugal 

Calibration: Darks, Flats, Bias. 

Processing: Calibrated, aligned and stacked in DSS. Post-processing in Photoshop.