Saturn and its companions

On March 18th, 2008, the weather was once again clear, but the Foehn wind was sweeping Northern Italys flatland, as it has (too) often happened during this past winter. No surprise the seeing was really crappy. In spite of that, I managed to pull off the following image featuring Saturn roaming the heavens with five of its satellites!

The satellites in the above picture are numbered as follows (verified with WinJupos): 1, Japetus; 2, Rhea; 3, Tethys; 4, Dione; 5, Titan

Some technical info on the above image:

• Telescope: Celestron C11 riding on a G11 mount
• Camera: Lumenera Lu075 at the C11’s prime focus
• Seeing: godawful (around 3-4/10) 🙁
• Exposure time: B/W movie @15 fp; 62 ms exposure time for the satellites (Saturn completely burned out), 2.5 ms exp time for the planet (satellites invisible). This yielded two separate exposures by stacking around 300 out 500 frames for each image.

Composite image made in Photoshop CS3