Cassiopeia Observatory

ISS, Mars/Mercury Conjunction,
IC342 Galaxy, NGC2359 Thor's Helmet
Posted: 8 February 2013

The observatory was opened Thursday, 7 February 2013, at 1801 MST, 70°F. There were some clouds low in the western sky where Mars and Mercury were. I immediately began setting up for the night's ISS pass, which was to occur in about 25 minutes. I first updated the ISS TLE in the telescope. I then mounted the D7000 DSLR at prime focus of the 8" LX200-ACF, focused on Mercury (instead of Sirius, which was behind a tree), locked the focus, and checked the finderscope alignment. At 1814 MST, I was ready for the pass to begin.

This night's ISS pass was not as good as on the previous night. It was a low pass across the sky, hence the ISS was further away from the observatory and so it appeared smaller and viewed through more atmosphere than the previous night. Tracking during the pass was fairly good most times. I captured these images of the International Space Station from the HD video, 1/2000sec, ISO 2500, showing the changing perspective during the pass:

After the ISS pass was over, I removed the camera from the telescope and at 1843 MST, I took this photo of Mars (top) and Mercury (bottom), f/4.8, 1/20sec, ISO 500, 155mm:

At 1845 MST, viewed Mars and Mercury using 7x50 binoculars. Pretty sight. I then viewed both planets in the same field-of-view in the 8" telescope at 77X. That was neat. Unfortunately, by this time both planets were well into a low tree and so I wasn't able to get an image through the telescope. Mars and Mercury have their closest conjunction on Friday, 8 February 2013. Weather permitting, I hope to photograph the close conjunction.

Beginning at 1907 MST, I began viewing some deep sky objects (DSOs) through the 8" telescope at 77X and 222X (Explore Scientific 2" 9mm 100° eyepiece). First was M42, the Great Nebula in Orion. Next was NGC2392, the Eskimo Nebula. The view of the Eskimo Nebula was very nice at 222X, especially with averted vision. Lots of structure was visible. I then switched back to the 1.25" 26mm eyepiece (77X) and viewed the Eskimo Nebula; still a nice view. Then viewed M44, the Praesepe open star cluster, 77X. Next, I viewed some DSOs selected from Observer Pro on my iPhone: M79 (globular cluster), NGC2237 (Rosette Nebula), and M67 (open cluster). At 1956 MST, I noticed some increasing clouds to the south.

At 2003 MST, I began an AutoStar tour of DSOs in the constellation of Camelopardalis, 77X: IC342 (a large but faint spiral galaxy), NGC1502 (open cluster), and NGC2403 (spiral galaxy).

At 2015 MST, I returned to IC342 (spiral galaxy) and began preparations to image it at prime focus + off-axis guider. I did a focus test on the star Capella using the Bahtinov Mask. I located a faint guide star and did a framing test exposure of IC342. I then captured this image (cropped), guided, 5 minutes, ISO 6400:

The image was desaturated in post-processing to better show the spiral arms. I plan to take a longer exposure on a future session.

Clouds were still increasing in the south at 2045 MST. After I completed imaging of IC342, I saw a tweet on my iPhone from the Mt Lemmon Sky Center with a photograph of NGC2359, Thor's Helmet. Since my D7000 DSLR was still mounted on the 8" telescope, I decided to try to image it myself. I slewed to NGC2359, found a good guide star, and did a framing test exposure. I then did a 5 minute, guided, ISO 6400, exposure. This is the resulting, slightly cropped, image:

Thor's "helmet" should be obvious. I will do a longer exposure on a future session to bring out some more of the faint nebulosity.

I completed imaging at 2105 MST. Clouds in the south and west were now covering more of the sky. I viewed NGC2359 (Thor's Helmet), 77X. Some nebulosity was faintly visible through thin clouds.

Comments are welcome; use the Comments section below, or you can Email Me. Thanks.