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Monday, October 19, 2009

Cat's Eye Nebula

In Natural Colors and In HST-palette

Uh, this was difficult.
Outer shell is very dim and the core of the Nebula is so bright, balancing that is not an easy task.
I'm happy with this result!
The core of the Cat's Eye Nebula has a small angular diameter, so good seeing is needed to reveal any internal details. I managesd to get some visible by using seceral relatively short exposures, 150s. each, for the core. Seeing varys between 3-2,2 FWHM.
There is a hint of cocentric circles visible around the core, ,they are real phenomen coused by polarized light from the nebula.

Gropped center from the image above.
They are very well seen in Hubble's image of the Cat's Eye Nebula HERE:
Two color chemes, HST Palette as S-II=Red, H-a=Green and O-III=Blue. Second image is in natural colors composed from narrowband data. Channels are balanced so, that image match to visible spectrum, H-a + 24%S-II=Red, O-III=Green and O-III + 15%H-alpha=Blue. - Processing work flow: Image acquisition, MaxiDL v5.07. Stacked and calibrated in CCDStack. Deconvolution with a CCDSharp, 30 iterations. Levels, curves and color combine in PS CS3. Mild wavelets to the core with RegiStax5 - -Telescope, Meade LX200 GPS 12" @ f4.65 Camera, QHY9 Guiding, SXV-AO @ 11Hz Image Scale, 0,8 arcseconds/pixel Exposures: H-alpha 9x1200s Binned 1x1 + 22x300s Binned 1x1 for the Core O-III 12x1200s, binned 1x1 + 15x150s Binned 1x1 for the Core S-II 4x600s, binned 1x1
- Total Exposure time is 10 hours.

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