Backyard astronomy in the suburbs

Double stars: Alpha Ursa Majoris

On the 26th of april 2020 I observed four double stars in Ursa Major. My favorite for the night was Alpha Uma, a very special binocular double. The mag. 2 A-component has a yellow orange colour, which contrasts beautifully with the mag. 7 blue white B-component. The stars have a separation of 381", so it is very wide. There are lots of weaker stars in the field, and I think the limiting mag is about 9.4. The view is very pretty!

The observation was made with a Fujinon 10x70 (fov 5.3 degrees), mounted on a mirror mount (north/south is flipped) Seeing and transparency good, very stable conditions. No clouds. South is up and west is to the right. The sketch is made with pencil, and later processed with Affinity Photo.

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