M 17 Omega/Horseshoe Nebula

OTA: AP175 (f/8) RCOS (14.5” f/8) TOA150 (f/7.3)

Camera: FLI - PL16070AE SBIG STX-16803 FLI - ML16200

Location: New Mexico New Mexico El Sauce, Chile

EXPOSURES:

Red: 17 x 600 sec ------ 16 x 900 sec

Blue: 6 x 600 ------ 15 x 900

Green: 9 x 600 ------ 16 x 900

Lum: 11 x 600

Hα: ------ 8 X 1800 sec 16 x 900

SII: ------ 4 x 1800 ------

OIII: ------ 4 x 1800 ------

Total exposure ~31 hours

Image Width: ~1/2 deg

Acquisition by DSW

Processed by Alex Woronow (2019) using PixInsight, StarNet, Gimp, Aurora HDR, Topaz, Matlab

M17 lies between 5,000 and 6,000 light-years away and it spans some 15 light-years in diameter. The nebula almost can be seen by the naked eye (magnitude ~6), and is easily seen in binoculars.

It is one of the most massive star-forming regions of our galaxy. An embedded open cluster of young, hot stars with abundant ultra-violet radiation, causes the gas in the nebula to ionize and radiate.

Although a plethora of young stars occur in this nebula, most are hidden within the nebula. The most active star-forming area, as imaged in professional infrared images, is in the rough-looking region toward the lower right of the main nebula. Often dark areas indicate active stellar winds blowing the dust and gas away from newly formed stars. This appears to be the case for this region of M 17.

Processing: All images were aligned to the RCOS frames, the highest resolution images. Using a proportional-mixing algorithm (using my physics-based version), narrowband contributions augmented their “true color” equivalents in RGB. The resulting color image was photometrically calibrated in PI; because of star-size mismatches, applying SCNR(green) rectified some star-core color distortions. A portion of the L channel extracted from the RGB augmented the L images from the AP175 Star Fire. StarNet removed stars from the resulting L, and Matlab (plus other referenced apps) sharpened the structures in M 17. Finally, recombining the component images produced the presented here.