Instrument

12.5" RCOS @  ~f/9 (2880 mm fl) 0.64 arcsec / pixel.  The Zoomify image scale is 1.28 to 3.07 arcsec / pixel.

Mount

Paramount ME

Camera

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

Acquisition Data

9/11/2010 to 10/1/2010 Chino Valley, AZ... with CCDAutoPilot3 & CCDSoft.  AOL guided

Exposure

SII                540 min (18 x 30 min, bin 1x1)

Ha                 480 min (16 x 30 min, bin 1x1)

OIII               510 min (17 x 30 min, bin 1x1)

Lum (no filter) 225 min (15 x 15 min, bin 1x1)

RGB               315 min ( 7 x 15 min each, bin 2x2)

SII, Ha & OIII are mapped to RGB respectivly with 25% LRGB data added.

Click here for the RGB natural color image.
Click here for the B & W Ha filter image

Software

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

• PixFix32 (pre-beta) to repair column defects.

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

• PhotoShop for SII, Ha and OIII color combine,  on-linear stretching and adding 25% LRGB

North is to the top.
 

Sh2-155, The Cave Nebula, is a faint area of Ha emission and dust in the constellation of Cepheus. The nebula gets is name from the darker area, at the center left, which visually appears as a cave. This highly stretched image brightens the cave and shows some of its structure.