Reflection nebula in Cepheus

Uploaded 11/28/2001

This beautiful reflection nebula in Cepheus fills the field at 14 acrmins in size. An inner blue nebula is surrounded by a cocoon of pink and red dust, that tapers off to invisibility in the surrounding field. The open cluster NGC7023 can be seen in the dark nebula to the right composed of several dozen faint stars. This nebula has a distinctly smoky outer boundary, causing many of the stars behind the nebula to have a ruddy or yellowish tint. The brilliant central star, is 7.4th magnitude, and presents an unusual challenge in processing to keep the blooming under control.

In the year I have been using CCDs, this object was one of the most difficult to find an off axis guide star on. The nebula itself is enclosed in a huge dark nebulous void, nearly starless, and the only guidestar available required a 16 second exposure on the blue filtered frame.

Processing: Six ten minute shots were calibrated by dark and flat fielding, and the six frames added. DDP was applied to this luminance frame. The RGB data was each two ten minute shots, with a weak DDP to ensure color would be available to the outermost regions. Registration in Picture Window Pro, and LAB combine in Photoshop 6.

Instrument:  12.5" f/5 Home made Newtonian
Platform:  Astrophysics 1200 QMD
CCD Camera:  SBIG ST7E w/Enhanced Cooling
Exposure:  LRGB = 60:20:20:40 (RGB Binned 2x2)
Filters:  RGB Tricolor
Location:  Payson, Arizona
Elevation:  5150 ft.
Sky:  Seeing FMHW = 1.9 arcsec, Transparency 8/10
Outside Temperature:  15 C
CCD Temperature:  -25 C
Processing:  Maxim DL, Photoshop, AIP4WIN, PW Pro.




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