April 26, 2008


Provided by: Rick Stankiewicz
Summary author: Rick Stankiewicz 

The photo above showing the dwarf planet Ceres was taken near Peterborough, Ontario, on November 11, 2007. With clear skies and armed with the finder chart from "SkyNews" magazine, I was able to accurately point my Canon XTi digital camera (mounted on an ETX telescope) toward the constellation of Cetus. The resulting photo shows the fruits of my labor, as I imaged Earth’s closest and smallest dwarf planet for posterity. By carefully comparing the final image to a detailed sky atlas, it was easy to determine that the 7.3 magnitude object in this image was in fact Ceres. I had just missed opposition on November 9th but it was still plenty bright enough to record. It's a great experience when the planets align, even if they're only dwarf planets. Click on photo for larger view.

Ceres is large enough to create its own gravity. This makes it nearly spherical, though somewhat larger at the middle. Calculations of the size of Ceres vary due to the nature of the measuring systems and the tools used. An analysis of several recent methods suggests that it is likely to have an average radius of about 295 miles (475 km). Accurate measurement is not possible until Ceres is visited. NASA's DAWN mission to study Ceres and the asteroid Vesta, launched September 27, 2007. The spacecraft is scheduled to arrive at Ceres in February of 2015.

Photo details: Canon EOS Digital Rebel XTi camera, 70 to 300 mm lens, which I piggyback mounted on a Meade ETX-90 telescope.