- Image for 2006
Galaxy in Camelopardalis
Instrument: 12.5" f/5 Home made Newtonian
Mount: Astrophysics 1200 QMD
CCD Camera: SBIG 10XME NABG with Enhanced Water Cooling
Guider: SBIG ST4 w/Lumicon Newt Easy Guider
Exposure: LRGB = 80:40:40:40 (RGB Binned 2x2)
AstroDon RGB Combine Ratio: 1: 1.05: 1.11
Location: Payson, Arizona, Elevation: 5150 ft.
Sky: Seeing FWHM = 4.5 arcsec (Maxim DL - 10min subframe), Transparency 8/10
Outside Temperature: 35 F
CCD Temperature: -30 C
Image Processing Tools:
Maxim DL: Calibration, Deblooming (Starizona Debloomer), aligning, stacking
Gralak's Sigma: Stacking
PixInsight: Curves, Deconvolution, noise reduction
Photoshop CS2: Curves, Color Correction, Gradient removal (Grad Xterminator), Cleanup
HOME GALAXIES EMISSION NEBS REFLECTION NEBS COMETS
GLOBULARS OPEN CLUST PLANETARIES LINKS
This years rendition
of this splendid face on spiral in Camelepodarus incorporates
the latest processing techniques, and plenty more color data
for a rich and very low noise presentation. NGC2403 is a low
surface brightness inclined Sc spiral, rated at an integrated
magnitude of 8.9, which is spread out to a rather thin 25 arcseconds
in size - about half a degree long here. North is up in this
view, and the galaxy is inclined about 5 degrees from face on
for our view from the Earth. Additionally, this galaxy is very
dust obscured, with a B-V index of.47, meaning it photographs
as nearly pure yellow. Histogram equalization was able to easily
correct for this discoloration, presenting the galaxy in a more
true color appearance.
Note the warped
extensions in the outer most blue arms. The lower left side warps
down, and the upper side warps up. Is this faint outer spiral
detail, or an anomalous distortion? You decided. This is a standard
LRGB image, with no extra Halpha added. This is coming next.
I've left the brightness of the sky background slightly light
so you can see the faint arms and some of the dim 18th magnitude
background galaxies. And to answer a question that everyone asks
me - Why are the diffraction spikes oriented 45 degrees from
North - South? Because my square tube on the 12.5" has the
vanes for the spider mounted from corner to corner on the box.
Some day I may change this.
L channel was enhanced to bring up the faint arms by layering
screened duplicate over the image, with a negative image of the
galaxy itself as a layer mask. To do this totally undocumented
trick and use an actual image for a layer mask, first make a
normal all white or black layer mask. Click the mask while holding
the Alt key down. Your image on the screen becomes the mask.
Paste over it a negative of the actual image. It converts to
greyscale automatically, and BECOMES the layer mask. Click back
on the main image to see the result. You can now vary the contrast
of the image layer mask with Levels or Curves and achieve a totally
spectacular masking effect.