NGC891 resides in the constellation of Andromeda.
The observing conditions were suboptimal due to poor sky transparency; stars were only visible down to about magnitude 4.3. However, there was no moonlight to interfere, only the light pollution from the city. For imaging, I utilized an Atik 383L mono CCD camera, a ten-inch f/4.8 reflector, a Vixen Atlux mount, and a set of Astronomik RGB and narrowband filters with PHD autoguiding. I captured five-minute subframes and integrated them with corresponding dark frames and flat field frames to mitigate noise and vignetting effects in the final image.The cumulative exposure time was 120 minutes with an HA filter, 40 minutes with an OIII filter, and 20 minutes with a blue filter.
