M 101

About image
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.

Technical data
Optic            Apo refractor Tecnosky 115/800 f/6.9
Mount          Losmandy G11 with FS2
Camera           Canon 400D Baader modified
Filters        -
Guiding system      Apo refractor Skywatcher 80ED
Exposure details    33x480" iSO 800
Total integration    4.4h
Acquisition        Maxim, PHD2
Processing        Maxim, Iris, Photoshop CS5
SQM-L          21.3    
Location         Pian dell'Armà (Pavia,

© Roberto Marinoni 2019 - All rights reserved