Instrument

12.5" RCOS @  ~f/9 (2880 mm fl) 1.28 arcsec / pixel.  The Zoomify image scale is 1.28 to 3.20 arcsec / pixel.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ internal filter wheel, AstroDon Gen I Filters

Acquisition Data

6/26/2010 to 7/15/2010 Chino Valley, AZ... with CCDAutoPilot3 & CCDSoft.  AOL guided

Exposure

Hα                  510 min. (17 x 30 min. bin 2x2)

OIII                570 min. (19 x 30 min. bin 2x2)

Lum (no Filter)  360 min. (24 x 15 min. bin 2x2)

RGB                180 min. ( 4 x 15 min each, bin 2x2)

20% Ha was added to the Red channel and 20% OIII to the blue.

Click here for a narrowband color mapped version.

Click here for an Ha filtered b/w image.

Software

• CCDSoft, CCDStack, Photoshop CS w/ the Fits Liberator plugin. Noel Carboni's actions.

• eXcalibrator for (b-v), (v-r) color calibration, using 7 stars from the NOMAD1 database.

• PixFix32 (pre-beta) to repair hot/cold pixels and column defects.

• CCDStack to calibrate, register, normalize, data reject, combine the sub exposures.

• PhotoShop for color combine &  on-linear stretching.

North ~ to the left.  The image is rotated 70° CCW

DWB-111, the Propeller Nebula, is an emission nebula in the constellation Cygnus. Astronomers seem to have more questions than answers, regarding this nebula. The origin of the peculiar structure is still completely unknown. The nebula's distance and source of excitation are also undetermined. DWB-111 mass is believed to be quite low, probably less than 50 solar masses. Obscuring dust is closely associated with the nebula, but seems to occur mostly in front of it.