The Sharpless 171 is one of the most northerly objects visible at the
observatory. It lies just outside of the band of the 2014 Cassiopeia
to Cygnus Project mosaic, but will be incorporated into that mosaic
(hopefully in 2015). Test shots showed extremely weak Oxygen and
Sulfur. As an experiment I doubled my normal narrowband exposure to 30
minutes for those two filters.
The processing of these images was greatly influenced by the 2014 Katonah NY
Pixinsight workshop. Applying what I learned in Katonah gives an image
that is much richer in color. Without the color processing Green
(Hydrogen) would dominate the image. The rich colors along the edges of the
nebula become apparent in the more balanced image. By using longer
exposures for Oxygen and Sulfur I did not have to as greatly multiple the
two channels to achieve a color balance. This improved the signal to noise
of the final product.
It should be noted that the final image no longer represents the amounts
of the three elements. It does make it easier to see the distribution
Zoomable Image in SHO
The full size image is just under 4096x4096. The following will allow
the reader to zoom into the image to explore it more closely.
Data was collected in September and October 2015 at -25C. Hydrogen was
collected at my standard exposure of 900 seconds (15 minutes). Oxygen
and Sulfur were collected for 30 minutes. The 1100AE was self guiding
through all exposures.
All images were processed by Pixinsight.
For general details on the processing of this image see.
I discuss the masks I used to create this project here.