Astro Session - October 4, 2017

October 4, 2017

Astrophotography with a full moon! I switched to narrowband imaging a few days ago, which has the advantage of limiting the light to a very narrow range, and not really being affected by the light of the sun reflected off the big smiling face of our moon. The requirements are far stricter than color or LRGB imaging in terms of exposure times (10 - 30 minute exposures are typical), which in turn require far tighter alignment for the mount and guiding system. I have three narrowband filters--Ha (hydrogen alpha) OIII (oxygen) and SII (sulfur), all with 6nm bandpass. For these images below I'm only imaging with the Ha filter and the Atik 414EX monochrome CCD camera. Image info: top-left: IC 1848 Soul Nebula (the center portion), bottom-left: IC 1369a Elephant Trunk Nebula, right: NGC 281 Pacman Nebula. 4 x 20 minute (1200 second) subs stacked in DSS.