Astrophotography by Keith B. Quattrocchi

 NGC 7822 
 Emission Nebula in Cepheus                           
 Narrow Band Image: (SII-Ha-OIII) + (NII)

 Astronomy Magazine's Picture of the Day: September 28, 2011
                
Copyright 2011
Keith B Quattrocchi

Image Acquisition Information                      
Telescope: 16" RCOS Richey Chretien Telescope (ion milled at 6/9) 
Camera: BIG STL-6303 M
Guiding: SBIG AOL,  strodon  MOAG AOG (SBIG 237 with Custom FLR)
Filters:  Astrodon Ha, NII, OIII (3 nm filters)
Mount:  Software Bisque Paramount ME
Acquisition Programs:   The Sky,CCDAutopliot III, CCD Soft. 
Processing Programs: CCDStack, Maxim DL, Photoshop
 Date: Data processed June 2011.  Data aquisition: September 22, 2010-November 6, 2010                              
 Time: 16 x30 min ( 8 hours) each for each of Ha, SII, NII and OIII:
 Total of  32 hours imaging time.                              
Processing:  CCD Stack and PhotoShop CS/3

Image Infornmation:  NGC 7822 is an emission nebula in the constellation of Cepheus.  The glowing star forming region which "lights" this nebula is about 3,000 light years away.  This object has relatively different patterns under NII and H-alpha filters, with a large central blue (OIII) component with less, but significant,  contribution in the SII region. 

 Additional Comments:  This Narrow Band image was obtained using  AstroDon 3nm band pass of Ha, NII and OIII.  This object sheds light in the Ha, SII, NII and OIII wavelengths.  The Narrow Band image was created by an unequal weighting of SII-Ha-OIII at a ratio of 6:1:14. This was essentially a modified Hubble Palette (RGB as Ha/NII/OIII).   This was layered over a modified (enhanced) N-II image to smooth out the noise and bring out some of the details lost in the assembled narrow band image.   Further data stretching, high pass filtering and background smoothing was performed with Adobe Photoshop CS/4.  All data stretching was by minimal stretching with gamma and DDP in CCD Stack and then further stretching with curves/levels in photoshop.