With weather looking wet and wild for the 2019 Cherry Springs Star Party and things looking slightly less soggy at Calhoun we decided to cancel on Cherry Springs and gamble on Calhoun. Good thing we were setup on the top of a ridge so we never had to deal with muddy conditions considering all the rain we didn’t know was coming.
I attended the annual Calhoun County Park Star Party (Oct 5-7) for the first time this year. The sky wasn’t the best it could be. Friday and Sat night both had humidity and dew off the charts with variable fog that seemed to slide up and down the hill but never got so high that it killed observing. I can’t help but think that it impaired the images a little but it may have just been the choice of a faint target during a hazy time of year. Sky quality measurements topped and held pretty steady around 21.6 mag/arcsec^2. I’m sure on a crisp night it would be a little darker. While there were some small light domes on the horizon they weren’t hardly worth mentioning in my opinion. The park was wonderful and the staff was so friendly they even prepared a great meal for us on Sat night. In total about 16 people showed for the party from TN, WV, PA, OH, and KY. Special thanks to Larry McHenry for posting info about the star party and turning us onto this event and Calhoun as an observing site. He typically posts updates on Cloudynights star party forum for upcoming Calhoun events.
Since Calhoun is pretty dark I decided to go after a fainter full spectrum object than I could ever do from home. VdB objects (reflection nebulae compiled by Sidney van den Bergh) are great targets when looking for something off the beaten path but aren’t always what I would call showcase objects. VdB 14 and 15 make for a nice parring here in a rich park of the sky in Camelopardalis.
I made the 13 hour trip up to Cherry Springs State Park for the Annual CSSP Star Party hosted by the Astronomical Society of Harrisburg PA, Inc. I went up a few days before the star party since it’s always helpful to get a good spot. Those of us that were there early on Monday night were treated to a fabulous night with SQM measurements >21.9! Overall it was an amazing streak of clear weather for PA with a total of 4 imaging nights. I was hoping for one or two so as not to set my expectations too high so I was very pleased with four nights!
I even did a little visual at low power with a 4″ refractor. LDN 1795 (large 50’x50’dark nebula in Scorpius) looked absolutely amazing to me at 19X. First time I had a WOW moment visually.
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.
MMOAG w/ ST-402
9.5 Hours Total Exposure
Baader Ha, O[III], S[II] filters
The Elephant’s Trunk nebula is a concentration of interstellar gas and dust within the much larger ionized gas region IC 1396 located in the constellation Cepheus about 2,400 light years away from Earth. The piece of the nebula shown here is the dark, dense globule IC 1396A; it is commonly called the Elephant’s Trunk nebula because of its appearance at visible light wavelengths, where there is a dark patch with a bright, sinuous rim. The bright rim is the surface of the dense cloud that is being illuminated and ionized by a very bright, massive star that is just to the west of IC 1396A. (In the Figure above, the massive star is just to the left of the edge of the image.) The entire IC 1396 region is ionized by the massive star, except for dense globules that can protect themselves from the star’s harsh ultraviolet rays.
The Elephant’s Trunk nebula is now thought to be a site of star formation, containing several very young (less than 100,000 yr) stars that were discovered in infrared images in 2003. Two older (but still young, a couple of million years, by the standards of stars, which live for billions of years) stars are present in a small, circular cavity in the head of the globule. Winds from these young stars may have emptied the cavity.
The combined action of the light from the massive star ionizing and compressing the rim of the cloud, and the wind from the young stars shifting gas from the center outward lead to very high compression in the Elephant’s Trunk nebula. This pressure has triggered the current generation of protostars.