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Tuesday, March 31, 2015

IC 1795 in the Heart Nebula

I spent hours in two nights by shooting this busy area in IC 1805, the Heart nebula, at 13. and 15. March.

IC 1795
Click for a large image

Image is in mapped colors from an emission of  the ionized elements. Golden areas are from emission of sulfur and hydrogen, S-II and H-alpha, blueish areas are from ionized oxygen, O-III.

A closeup
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IC 1795 is also known as a Fish Head Nebula. It's a  star forming region in the northern constellation Cassiopeia at distance of about 6000 light years. My image shows about a square degree of sky, the actual size of the imaged area is around 130 light years. IC 1795 is a part of the large nebula complex known as IC 1805, the Heart Nebula.

Image in visual spectrum
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Natural color composition from the emission of ionized elements, R=80%Hydrogen+20%Sulfur, G=100%Oxygen and B=85%Oxygen+15%Hydrogen to compensate otherwise missing H-beta emission. This composition is very close to a visual spectrum.

Image in emission of an ionized hydrogen only (H-alpha)

A two frame mosaic
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This photo of IC 1805 was partly overlapping with my previous image from the same area.
I made a small two frame mosaic out of them. I have shot more frames after this imaging project and now I'm able to make a high resolution mosaic of the whole IC 1805 area. I'll publish that later.

This two frame mosaic is in mapped colors. I have material for the whole IC 1805 area but I'll publish it later. Blog post about the Melotte 15 at the left part of the mosaic above can be seen HERE.

Orientation in IC 1805, the Heart Nebula
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The area of IC 1795 is marked as a white rectangle. 

Technical details

Processing work flow

Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Deconvolution with a CCDStack2 Positive Constraint, 33 iterations, added at 50% weight
Color combine in PS CS3
Levels and curves in PS CS3.

Imaging optics
Celestron Edge HD 1100 @ f7 with 0,7 focal reducer for Edge HD 1100 telescope

10-micron 1000

Cameras and filters
Imaging camera Apogee Alta U16 and Apogee seven slot filter wheel
Guider camera, Lodestar x2 and SXV-AOL

Astrodon filter, 5nm H-alpha
Astrodon filter, 3nm O-III
Astrodon filter, 3nm S-II

Exposure times
H-alpha, 15 x 1200s = 5h
O-III, 3 x 1200s = 1h min.
S-II, 3 x 1200s = 1h min.
Total 7h

A single un cropped, calibrated and stretched 20 min. H-alpha frame as it comes from the camera
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