Imaging: NGC6946, Caldwell 19, NGC253, Uranus, Jupiter
Posted: 9 October 2012
As I mentioned on my previous report, I was away from the observatory for a reunion of my USAF A-7D fighter squadron. I'm still editing the 500+ photos/videos that I took and will get them online as soon as possible. In the meantime, you can read the story about our reunion that was published in the Myrtle Beach, SC, newspaper. They have also posted a photo gallery.
I returned home on Wednesday, 3 October 2012, but the sky was cloudy. The sky finally cleared on Monday, 8 October, and after almost 3 weeks of no observing, the observatory was opened at 1804 MST, 85°F. I had a lot planned for this night. First, was a nice ISS pass at 1855 MST. I SYNCed the 8" LX200-ACF on the star Altair, reset the observatory clock using WWV, updated the ISS TLE in the AutoStar, mounted the D7000 DSLR at prime focus + 2X Barlow Lens, did a focus test on Altair using the Bahtinov Mask, locked the telescope focus, and checked the finderscope alignment. At 1840 MST, I was ready for the pass. I did a HD video recording, 1/1600sec, ISO 2000, for 5m25s. During the pass, tracking was not ideal (it rarely is) and during post-processing of the video, none of the frames were clear enough for use. I will go back to imaging the ISS at just prime focus on future opportunities.
At 1908 MST, I began preparations for DSO imaging. My initial targets were NGC6946 (galaxy) and Caldwell 19 (diffuse nebula). I had imaged both on 17 September 2012 using single 5 minute, ISO 6400, exposures. The plan for this night was to take four 5-minute, ISO 6400, exposures of each DSO and stack the images using Lynkeos. Mounted the DSLR at prime focus + Off-Axis Guider, did a focus test using Vega with the Bahtinov Mask, then slewed to NGC6946 and did a framing test exposure, 1 minute, ISO 6400. A faint guide star was found and four good, guided, 5 minute, ISO 6400, exposures were captured. This is a stack of the images, effective exposure 20 minutes:
I then slewed to Caldwell 19 and did a framing test exposure. A faint guide star was found and four 5 minute, ISO 6400, guided exposures were captured. Unfortunately, guiding was good on only three of the exposures, yielding this effective 15 minute, stacked image:
Finished imaging at 2034 MST, removed the camera from the telescope, and added a focal reducer in preparation for my next imaging target: NGC253 (Sculptor Galaxy) and NGC288 (large but faint globular cluster). At 2046 MST, viewed NGC253 in the 26mm eyepiece + focal reducer, low in the southeast. Then slewed to NGC288. I could not get both objects in the same FOV with the 26mm + focal reducer. Using a 2" 50mm eyepiece + focal reducer I was able to see both objects in the same FOV but they were both at the edge of the field and the view was not very good. I would try imaging both once they were higher in the sky.
Beginning at 2115 MST, did some 7x50 binoculars observing: M31, Pleiades, Double Cluster, and the Milky Way overhead (in Cygnus).
I then switched to a visual back + focal reducer on the 8" to check the needed camera orientation for my attempt to image NGC253 and NGC288. Having decided on the camera orientation, the camera was mounted at prime focus using the Off-Axis Guider at 2200 MST. I did a preliminary visual focus test (without the Mask) on the star Fomalhaut and began trying to get both DSOs in the D7000 DSLR FOV. I could see each object in the camera viewfinder but was not successful in getting both in the FOV at the same time. They were just slightly too far apart. I decided to just image NGC253 with the focal reducer and OAG. Did a focus test exposure on Fomalhaut with the Mask. I captured this cropped, guided, 5 minute, ISO 6400, image of NGC253:
I ended DSO imaging at 2230 MST, removed the camera and focal reducer. At 2243 MST, viewed Uranus and Neptune, 77X. I then set up for eyepiece projection imaging with a 9mm eyepiece (222X). Slewed to Uranus, focused using Live View on the D7000, and a 2302 MST, took this ~1sec ("Hat Trick"), ISO 1600, cropped image:
I then took this ~1sec ("Hat Trick), ISO 500, cropped image of Jupiter:
Although Jupiter was still somewhat low in the east, I decided to try a HD video as a test. This eyepiece projection (222X), 1/30sec, ISO 500, 17 second video was stacked (426 frames) using Keith's Image Stacker:
The frames were slightly underexposed; I'll use a higher ISO next time.
I ended imaging and did some Jupiter observing, 77X and 206X. While I was observing Jupiter, I kept hearing some odd sounds inside the observatory. I finally located the source, which was this visitor:
I was able to eventually escort him out.
I resumed Jupiter observing; four moons were visible. At 2329 MST, I noticed some clouds in the south. At 2339 MST, checked on the asteroids Ceres and Vesta but they were currently too low in the sky. I returned to Jupiter; only three moons were now visible. At 2347 MST, the clouds in the south were getting higher in the sky. I began setting up to image Vesta. Mounted the D7000 DSLR at prime focus using the star diagonal and did a focus test on Aldebaran with the Mask. I then slewed to where the AutoStar II thought Vesta was located and did an unguided 1 minute, ISO 1600, exposure. During post-processing, I compared the image field with Vesta's location as shown in SkySafari Pro for Mac OSX. Unfortunately, Vesta was just outside the image field. Will try again on another session.
Clouds were now over much of the southern half of the sky so I decided to end the session. It was nice to have been back in observatory.
The observatory was closed at 0018 MST, 67°F.
Comments are welcome; use the Comments section below, or you can Email Me. Thanks.
Go to the previous report.
Return to the Cassiopeia Observatory Welcome Page.