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D7000 DSLR Telephoto: Comet C/2011 L4 (PanSTARRS)

Posted: 6 June 2013

The observatory was opened Wednesday, 5 June 2013, at 1836 MST, 100°F. The sky was clear and for a change, there was no breeze. Beginning at 1843 MST, I started viewing Mercury, but seeing was not very good. I immediately set up for iPhone video recording with the hope that I might capture a few good frames that would show the surface detail I've been detecting visually for the last few nights. I used the #21 Orange filter at 444X. I continued to take videos until Mercury was too low in the sky. Unfortunately, none of the videos had any usable frames due to the poor seeing. I will try again on the next session. I resumed observing Mercury at 1915 MST, 364X + Orange filter. Seeing was bad. At 1917 MST, seeing momentarily improved and I could briefly see the surface detail. I ended Mercury observing at 1925 MST.

Viewed Saturn, 133X, at 1927 MST. Sunset was at 1930 MST. I checked the finderscope alignment for the ISS pass to occur later. Updated the ISS TLE. Continued observing Saturn. At 1951 MST, four moons were visible: Titan, Dione, Tethys, and Rhea.

At 2008 MST, the first Kissing Bug of the night landed on my arm! I knocked him to the floor; he was terminated with extreme prejudice.

Back at the 8" telescope, I tried to view Saturn's moon Enceladus using 133X. I have seen it in the past, and it should have been visible this night. But I did not pick it up. At 2022 MST, seeing was getting worse. I ended Saturn observing at 2033 MST to prepare for the ISS pass.

The ISS pass was another low elevation one so I did not try to image it. I observed it through the 8" telescope at 133X. The first and last thirds of the pass had good tracking. Viewing the middle third of the pass was hampered by poor tracking, which is typical of ISS passes as the station nears the North Celestial Pole (NCP). When tracking was good, I had some great views of the space station. The solar panels were a nice gold in color.

At 2105 MST, I began preparing to image Comet C/2011 L4 (PanSTARRS). On the previous night, I had imaged the comet through the 8" telescope. This night I imaged it with the D7000 DSLR piggybacked on the 8" telescope. I set the 70-300mm lens to 300mm and focused on the star Vega. I powered on the GC Wi-Fi Adapter and used SkySafari Pro on the iPhone 4 to GOTO to the comet. I wanted to manually guide on the comet using a reticle eyepiece on the telescope, but since the comet was near the NCP, the eyepiece was in an awkward position on the wedge mounted telescope. I decided to just let the telescope track the sky during the exposures. I did several framing tests at 300mm, but that was too much focal length. I set the lens to 140mm and did more framing tests. Finally, I was happy with the framing and did 1, 2, and 5 minute exposures at ISO 1600, 3200, and 5000. This full-frame image is a 5 minute, ISO 5000, exposure, desaturated to best show the comet and its long "anti-tail" and its shorter "dust tail":


I ended comet imaging at 2225 MST and tried to see the comet using 7x50 binoculars. Didn't see it. I then viewed the comet with the 8" LX200-ACF at 83X. The comet's coma and short tail were visible.

I then did some deep sky object (DSO) observing, 83X. First was M57 (Ring Nebula, planetary nebula) and M56 (globular cluster) in Lyra. Also, viewed Epsilon Lyrae (Double-Double Star). In Cygnus, I observed NGC6819 (Foxhead Cluster, open star cluster), NGC6826 (planetary nebula), NGC6888 (Crescent Nebula, diffuse nebula), M29 (open cluster), NGC6960 (Veil Nebula, diffuse nebula), IC5067 (Pelican Nebula, diffuse nebula), NGC6992 (diffuse nebula), M39 (open cluster), and IC5146 (diffuse nebula). Next was M71 (globular cluster) in Sagitta (added to imaging list) and NGC6934 (globular cluster) in Delphinus.

The observatory was closed at 2335 MST, 73°F. Fourteen Kissing Bugs were terminated this night, most of them between the hours of 2000 and 2200 MST, with one straggler at 2329 MST.

I have added some recent videos done at Cassiopeia Observatory to the Videos page.

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

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