Object: Constellation: Coordinates: Size: Brightness:
NGC 3945 Ursa Major 11h53m / +6041' 5.2' x 3.5' 10.9mag

The lenticular galaxy NGC 3945 in the constellation Ursa Major on March 27, 2017. The galaxy is intermediate between an elliptical and a spiral galaxy and was discovered by the British-German astronomer William Herschel in 1790. (source: Wikipedia).

Fourty-three exposures of approximately 3 minutes at ISO 800 were stacked with no dark frame subtraction with Deep Sky Stacker (resulting in a 2 h 24 min exposure) and further processed in Photoshop. This galaxy would need far more exposure time to reveal more of its beautiful ring structure. Sky transparency was mediocre.
Equipment: Canon EOS 450D Baader modified camera, TeleVue Paracorr Type II coma corrector, 16" f/4.5 "Ninja" dobsonian telescope riding on a dual-axis Tom Osypowski equatorial platform, Lacerta MGEN autoguider, Lacerta off axis system (field of view comparison: image of the moon with the same equipment).

Search chart for NGC 3945. Map © 2017 "The Mag-7 Star Atlas Project", www.siaris.net. Map is modified. The map can be downloaded here .