M 81, M 82 

Spiral galaxy M81 (Bode’s galaxy) is located at a distance of 12 Mill. light-years, or 3.7 Mpc. The diameter is about 95.000 light -years, about the same size as our Milky Way galaxy. The irregular starburst galaxy M82  is at about the same distance as M81, but only half of its size. Both galaxies are located in constellation Ursa Major (Big Dipper) and are part of the Virgo super-cluster of galaxies.

Galaxies M81 & M82,  8 April 2016, Noordwijk, William Optics 110 mm APO FLT f/7, Canon EOS 600D, UV-IR, UHC filter, 800 ISO, 3x30 sec stacked, fitswork

The picture above is my first attempt with the Canon DSLR, short exposure, only 90 seconds. M81 (left) and M82 (right) are just visible. 

Using the monochrome ASI1600mm pro in Spring 2022 and Spring 2023, a deeper exposure of M81 with auto-guiding was obtained (see below) using broad-band filters L, R, G, and B.

Galaxies M81 (centre) and M82 (bottom right),  28 February 2022, 27 & 28 March 2023, Kempen, William Optics 110 mm APO FLT f/7, ASI1600mm pro, LRGB, L(4800 s), R(3360 s), G(3360 s), B(3960 s), gain 139, T: -10C, Image processing with PixInsight V 1.8.9

Finally, additional short (10 sec) exposures (without auto-guiding, L-filter) on M81 alone, obtained in 2022, were added as well. The resulting gray-scale image is shown below.

Galaxy M81. 11, 12, 28 February 2022 & 27, 28 March 2023, Kempen, William Optics 110 mm APO FLT f/7, ASI1600mm pro, LRGB, 

L(5720 s), R(4280 s), G(3610 s), B(4140 s), (converted to grayscale), gain 139, T: -10C, Image processing with PixInsight V 1.8.9