NGC 891, a 10th magnitude spiral galaxy imaged under a bright sky with a C11 SCT and LP filter

Peter Nerbun
Location of photo
Perry Hall, Maryland USA
Date/Time of photo
Mar 29, Apr 3, Apr 5 and Apr 8 2016
C11 SCT, IDAS LPS-P2-48 light pollution filter, On Axis Guider (ONAG), ATIK 460EX main imaging camera, Lodestar X2 guide camera, Losmandy G11 mount, RGB color and Luminance filters, F/6.3 Reducer, Starlight FeatherTouch fine Micro-Focuser, Orion Nautilus motorized filter wheel
This image shows NGC 891, a 10th magnitude spiral galaxy viewed edge-on; this galaxy is 32 million light years from Earth, its size is 123,000 light years or about 23% larger than our Milky Way. Because I image from a bright sky location in Perry Hall, Maryland I used an IDAS LPS-P2-48 light pollution filter; due to the spectral characteristics of this LP filter I was able to capture 15 minute images in the Red Channel each yielding a 20% histogram peak and a 10 minute image in the Luminance channel that yielded a 33% histogram peak. Both of these histogram measures fall within the ideal 20-40% peak levels that enable separation of the faintest object detail in the galaxy from camera noise. The total integration time for my image was 3 hours and 41 minutes.