M101, also called the "pinwheel galaxy", is a spiral galaxy in the constellation of the Ursa Major.
It is a Sc-type galaxy (non-compact spiral) seen exactly "in the face": its spiral arms are however very weak and visually visible only with large telescopes, while they are easy enough to reveal with long-exposure photographs.
Its distance from the Earth is about 24 million years ago, and its diameter is about 170,000 light years, so it is a galaxy that is considerably larger than our Milky Way.
Optic Apo refractor Tecnosky 115/800 f/6.9
Mount Losmandy G11 with FS2
Camera Canon 400D Baader modified
Guiding system Apo refractor Skywatcher 80ED
Exposure details 33x480" iSO 800
Total integration 4.4h
Acquisition Maxim, PHD2
Processing Maxim, Iris, Photoshop CS5
Location Pian dell'Armà (Pavia,