We’ve had far too many rainy days followed by isolation and the closure of astronomy parks and related facilities. Even if it cleared, we have nowhere to go. So here’s a quick reminder of the winter nebula that are leaving now not to be seen until next year. I wish I had time to do a mosaic and capture the whole nebula but I didn’t. It truly is a LARGE nebula. This image is 2.4 degrees across and could hold more than 18 full moons. (The moon varies between about 29′20″ – 34′6″ in size)
IC 1805 / Sharpless 190, more commonly known as the Heart Nebula, lies approximately 7,500 light years from Earth. This data set was comprised of 43x20min Ha, 23x20min O[III], and 24x20min S[II] for a total exposure time of 30 hours over several nights in November 2019.
We had a great clear spell 7/23 through 7/27 with only moderate lunar interference in the early hours of the morning. This is 14 hours of exposure divided equally across Hydrogen-alpha, Oxygen [III], and Sulfur[II] emission lines. Scope was an AP130GTX with Apogee U16 CCD on an AP1200GTO mount. Located outside Clinton, TN. The following are crops from the main image.
Finally, here is the nearly full frame image encompassing the whole area.
I recently replaced the dome control electronics after the Foster Systems controller bit the dust and I replaced with a MaxDome II controller for rotation and shutter operation. It’s working flawlessly so far and I couldn’t be happier. I threw the 5″ refractor back in the observatory with the 16803 chipped camera for a widefield rig at 2.2 arcsec/pixel resolution. Drizzle processing yields better star shapes/sampling than the low resolution would suggest. Both images are cropped from the same image with 20.5 hours of total exposure time in the traditional Hubble Pallet.
I was the first one to arrive for the star party on Saturday night at Look Rock South. It’s a beautiful view to the south looking into the Smokies.
We definitely had some clouds for the beginning of the night with some sucker holes now and then. I was never able to get off a 20 minute shot without the clouds rushing in within 10 minutes…
But things finally started to clear up and the Milky Way really started to pop out.
Once it was cleared up I was off to take some test shots and validate the portable rig was ready for more serious projects. NGC 6820 AKA Sharpless SH 2-86 and all the surrounding emission and dark nebula has always been a favorite of mine. It’s located in Vulpecula not that far from M27, the Dumbbell Nebula. It reminds me of a less popular M16 with it’s gas and dust pillars and dark globules. Open cluster NGC 6823 resides in the midst of the nebula and is about 6,000 light years away.
Cloudy winter nights have inspired a second look back at some fun summer targets. Here’s NGC 6871 in Cygnus.
Last year (2014) I was conducting some mosaic tests for future projects. I attempted a widefield 9 panel mosaic in Cygnus and processed the hydrogen alpha data but never got around to completing the tri-color Hubble Pallet image until now due to some difficult to process issues in the O[III] and S[II] channels. Those difficulties, combined with the fact that I only gathered about one frame of each channel per panel in the mosaic (very thin data!), meant that I wasn’t exactly thrilled to process this one to completion. Time away from the hobby due to the out of state relocation though has made me a little anxious to get back to imaging so I decided to revisit some of this forgotten data.
I began work on a tri-color Hubble Pallet image during the summer of 2014 but due to weather and other obligations did not capture much in the way of Oxygen [O III] and Sulfur [S II] emission data for the mosaic project so am leaving it as a monochrome image using only the Hydrogen Alpha emission line data.
It’s that time of year when Cygnus rises high over head and displays a multitude of nebulous treasure. This mosaic is only a portion of the Cygnus constellation but represents a large patch of sky almost 9 x 9 degrees. This is only a test framing as I create a game plan for a summer long imaging project. For a sense of scale, I have included a gibbous moon which was not part of the original image as well as a full scale crop of the Crescent Nebula, bottom right, to show the full size scale of the original 83 megapixel image.