Cassiopeia Observatory

Zodiacal Light, NGC660 Polar-Ring Galaxy

Posted: 12 January 2013

Clouds returned on Wednesday, 9 January 2013, as another winter storm approached. You can watch a time-lapse video of clouds going by on Thursday, 10 January. Overnight, about 1/2" of snow accumulated. Since the forecast for Friday night, 11 January, was for clear skies, I went to the observatory mid-day and cleaned snow off the dome. This capture from my live webcam shows me checking out some of the snow along the pathway to the observatory:

The observatory was opened at 1809 MST, 41°F. The sky was mostly clear. At 1816 MST, I took a quick look at Jupiter, 77X. Four moons were visible.

I then began preparing the D7000 DSLR for photography of the Zodiacal Light using the 8mm 180° fisheye lens. The camera was mounted on a photographic tripod, hence no tracking would be done. Exposures would be taken at f/5, 30, 60, and 90 seconds, using ISO 5000 and ISO 6400. At 1843 MST, the Zodiacal Light was visible even though twilight was not quite over. I began photography at 1855 MST, with this photo being taken at 1900 MST, f/5, 30 seconds, ISO 5000:

The camera was aimed upwards to capture all of the Zodiacal Light, which extended almost to the central meridian, hence the slight curvature of the horizon. The Zodiacal Light is about 1/3 from the left edge, and the Milky Way about 1/3 from the right edge. The "Great Square of Pegasus" is above center, with M31, the Great Andromeda Galaxy, faintly visible near the middle top edge. The SkyShed POD observatory and 8" telescope inside are at the lower right.

I completed Zodiacal Light photography at 1930 MST. It took longer than I had hoped as, unlike when I was doing all-sky photography test exposures using airplanes as stand-ins for meteors, this time I didn't want any airplane trails in the photos. I had several long delays while waiting for airplanes to pass by.

I then began setting up for prime focus imaging with the 8" LX200-ACF. At 1946 MST, I did a focus test exposure on a star using the Bahtinov Mask. The temperature was now 29°F in the observatory. I was glad I had some hot chocolate available!

I then slewed to NGC660, a "polar-ring" galaxy. I had imaged this galaxy on the previous session but I wanted to try to capture the "ring" better. This night I did four 5-minute, ISO 6400, guided exposures. The images were stacked using Lynkeos, yielding an effective exposure of 20 minutes. This is the result:

I finished imaging at 2020 MST. I took a quick look at M42, the Great Nebula in Orion, 77X. I then viewed the Eskimo Nebula at 77X and 222X. That seemed appropriate, considering the current temperature.

I finally had enough of the low temperature. The observatory was closed at 2043 MST, 29°F.

The 2nd Annual "Arizona Science and Astronomy Expo" will be held 16-17 November 2013 at the Tucson Convention Center in Tucson, Arizona. As I did for the 2012 Expo, I will be there in 2013, probably working both the OPT and SkyShedPOD booths. Start making your travel plans now.

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