segunda-feira, 6 de janeiro de 2014

Flame and Horsehead Nebulas

The Flame Nebula, designated as NGC 2024 and Sh2-277, is an emission nebula in the constellation Orion. It is about 900 to 1,500 light-years away.

The bright star Alnitak (ζ Ori), the easternmost star in the Belt of Orion, shines energetic ultraviolet light into the Flame and this knocks electrons away from the great clouds of hydrogen gas that reside there. Much of the glow results when the electrons and ionized hydrogen recombine. Additional dark gas and dust lies in front of the bright part of the nebula and this is what causes the dark network that appears in the center of the glowing gas.

The Horsehead Nebula (also known as Barnard 33 in emission nebula IC 434) is a dark nebula in the constellation Orion. The nebula is located just to the south of the star Alnitak, which is farthest east on Orion's Belt, and is part of the much larger Orion Molecular Cloud Complex. The nebula was first recorded in 1888 by Scottish astronomer Williamina Fleming on photographic plate B2312 taken at the Harvard College Observatory. The Horsehead Nebula is approximately 1500 light years from Earth. It is one of the most identifiable nebulae because of the shape of its swirling cloud of dark dust and gases, which bears some resemblance to a horse's head when viewed from Earth.




Image Data: Flame and Horsehead Nebulas

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
Exposure: 
Stack of 34 420-second exposures (3:58 hours 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: 400
White Balance: Custom
Filters: Astronomik CLS CCD
Dates: December 29, 2013
Location: Beja, Portugal
Calibration: Darks, Flats, Bias.
Processing: Calibrated, aligned and stacked in DSS. Post-processing in Photoshop.