MW7 - The Cow Nebula Section of the IFN
MW7 - The Cow Nebula Section of the IFN
MW7 - The Cow Nebula Section of the IFN
While many astronomical images show nebulae that are illuminated by the light from nearby stars or star clusters, this image shows an entirely different kind of reflection nebula. Surrounding our Milky Way galaxy are large clouds of dust, hydrogen, carbon monoxide, and other elements that have been ejected from our galaxy. The clouds are not illuminated by stars, but are illuminated by the entire light of the Milky Way Galaxy. Because of this, they are known as the Integrated Flux Nebulae or IFN - meaning that their light comes from the combination of all the light from our galaxy.

These clouds are mostly visible at high galactic latitudes - those portions of the sky that are well outside of the plane of the Milky Way. We see very large portions of the IFN in the regions towards the north near Polaris and other circumpolar constellations.

This image is a 2 panel mosaic showing a little over 6 by 6 degrees of a section of sky only 9 degrees south of the North Celestial Pole. It shows a portion of the IFN in the constellation of Cepheus known as the "Cow Nebula" or MW7 (Mandel-Wilson Catalog of Unknown Nebula #7). While the nebula is quite faint, it is one of the denser parts of the IFN. This image has been processed so as to bring out the nebula from the background sky.

Included in this image is the pretty open cluster, NGC 188 (at the top edge towards the right side of the image).

In this image, North is up.

Exposure Details
Lens Canon EF 200mm f/2.8L II USM
Focal Length 200mm
Focal Ratio f/3.5
Mount Schaefer GEM - 7 1/2 inch Byers gear
Guiding Piggybacked on Celestron C-8, ONAG On-Axis Guider, Lodestar autoguider, PHD Guiding
Camera Canon 450D - Gary Honis modified
Exposure 72 subs of 600 sec @ ISO 200 (12 hours total exposure)
Calibration 30 darks, 30 flats, 30 flat darks, 30 bias
Date December 25 and 26, 2013
Temperature 44F on 12/25, 51F on 12/26
SQM Reading 21.25 (Bortle 4) on both nights
Seeing 4/5 on 12/25, 3/5 on 12/26
Location Pine Mountain Club, California
Software Used Images Plus 5.75 for camera control, calibration, stacking, digital development, star shrinking, smoothing and noise reduction, multiresolution sharpening and Feature Mask. Photoshop CS5 used for levels and curves, screen mask invert, lab color, saturation adjustments, selective color, match color, and vibrance. Gradient Xterminator for gradient removal. Carboni Tools for additional noise reduction, and smoothing. Registar for aligning stacks.
Notes I had imaged the IFN for the first time last year with my image of the IFN surrounding M81 and M82. I decided I wanted to try a little more challenging and less commonly photographed section of the IFN, and MW2 seemed to be a good choice. The nebula fit the field of view of my 200mm well by doing a 2 panel mosaic, and its a comparatively bright part of the IFN. The image also gave me another chance to refine my skills using Image Plus' new Feature Mask tool to bring out the faint nebula.

While the image doesn't have the nice "eye candy" of the M81/M82 part of the sky, I think this nebulosity is quite beautiful. I'm very pleased with the final result in this image.