Cassiopeia is an astrophotographer's
dream! It is filled with shapely, beautiful emission nebulae.
This image portrays one of the most spectacular of those nebulae,
and perhaps one of the most unique objects in the night sky. Located
next to another emission nebula, IC 1848
(click here for image), the two together comprise
the Heart and Soul Nebula complex. This complex happens to be to
very close to another grand site, the Double Cluster in Perseus.
IC 1805 is the name for
the large, heart-shaped area of nebulosity, but many of the components
of this image have other designations. At the very center
of the "heart" is an open cluster of stars known as Melotte
15. This cluster can be seen with just about any telescope
as a couple of dozen stars, quite indistinct. The two bright
patches at the bottom are known separately as NGC 896 and IC
1795, from left to right respectively. At the left side of IC1805
is a line of stars known as Markarian 6. To observe the nebulosity
itself, you must have large apertures (over 16") and either
UHC or OIII filters. With such a setup, you should see NGC
896 as a faint glow, and perhaps even part of the arc of IC1805
itself. Averted vision might be the only way to see it, and
I shouldn't have to say it, but you'll also need dark skies.
Even though this object might
not be too pleasing through a scope, it certainly is with a camera.
To enhance the detail in the object, I employed a technique whereby I used a special
filter that captures the Hydrogen Alpha emissions of the nebula,
took parts of the image through it, and then used that information
to give the image a special luminance component. It is a difficult
technique to perform from a processing standpoint, but I'm quite
pleased with the result, which is a good thing, since this nebula
deserves a place in everyone's heart (pun intended).
Star Party, Eldorado, Texas
Temperature: -25 degrees C on camera
Scope/Mount: Tak FSQ-106 @ f/5
on Paramount ME
Camera: SBIG STL-11000M astro
Filter: Custom Scientific 4.5 nm H-alpha
Exposure Info: HaRGB
image; 160:50:30:60 minutes (10 minute subexposures for RGB, 20 minute
subexposures for Ha)
with CCDSoft. Calibration
(darks/flats), and registration in CCDstack
(median combine). LRGB
combine and Ha blending, color balance, levels/curves, and
noise removal/local contrast enhancement (Noel Carboni's Astronomy Tools) in Photoshop
Alpha Data used for image (160 minutes)
on the image for larger resolution (1600 x 1032 pixels)
Location: The Ballauer Observatory near Azle, Texas
Date: September 8,
Temperature: 60 degrees F
Seeing: 8/10, steady
Scope/mount: Takahashi FSQ-106 @ f/5 and Tak NJP mount
Filter: Custom Scientific 4.5 nm Hydrogen
Exposure Info: HaRGB image - 150:20:20:20 minutes (15
min. subexposures for luminance; 5 min. subexposures for RGB, binned 2x2).
Processing Info: Dark frame calibration, flat-fields, de-blooming,
registration, and average combine of all channels in MaxIm 4.0.
Digital-Development in MaxIm. Blending of final data, Levels, Curves, Unsharp
mask, Despeckle, and color balance in Photoshop CS.
Extra notes: The red
channel is blended 50/50 with the Ha luminance. Full luminance used on final
combine. Special thanks to Three Rivers Foundation (3RF) for the use of
some of the equipment used in creating this image.
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