Johann Bode is credited with the discovery of this galaxy pair in 1774, which were added to the Messier catalogue in 1781. M81 a grand design spiral, lying over 11.6 million LY away and spanning 90,000 LY shows plenty of detail. The spiral arms are tinged with blue star streams and are dotted with pinkish emission nebulae; at the core lies a huge black hole with a mass of 70 million sol.

The edge-on ‘starburst’ galaxy M82 sports strong hydrogen emissions streaming above and below a luminous core, induced by the gravitational interactions with M81, and numerous supernovae within the core of this amazing galaxy ~10 per year (according to Wikipedia).

After having so much trouble processing M101, with a strong circular gradient in the image, which I assumed was an issue with backspacing or calibration - this image was straight forward, using exactly the same imaging train... I can only assume that despite a dew strap and shield, there were issues with dew forming on the corrector plate that I failed to notice!

Data were collected using APT, calibrated, aligned and stacked in Nebulosity, and processed in Startools. I pushed the saturation a bit to show off the star streams, nebulae and starburst, which showed up well considering no Ha has been added. I continue to be very impressed by this OSC CMOS camera. I applied a little smoothing to the final image using the GreyCStoration tool in Nebulosity.

Revision C is actually the original image from Startools, with no correction to the stars. A rough polar alignment, resulted in less than ideal guiding leading to some elongation, and the stars around the periphery are awful with my f3.3 reducer. Using Han Klein's excellent CCD Inspector there is significant tilt and aberration - how much is due to poor collimation, mirror flop or other quirks of my SCT imaging train remains to be seen. In revision B, I have opted for a a little more blue to show off those beautiful star clouds.

As ever your comments, constructive criticism, general support and encouragement are always welcome.