Whirlpool Galaxy (Messier 51), revisited

The Whirlpool Galaxy, or Messier 51, is probably one of the most often imaged galaxy on the northern sky as it is comparable large but also has a rather unusual structure. In fact this is a larger spiral galaxy interacting with a irregular galaxy NGC5195.

Probably caused by this interaction Messier 51 has also a higher starforming rate. In this image I also captured H-Alpha to highlight these regions as they are rich of ionized hydrogen atoms.

But even with a focal length of 1000mm this still is a crop of the original image, which is shown here along with annotations:

The markings in turquise denote the many background-galaxies within this area.

I already imaged this area back in December 2021 with my 580mm APO (45min, OSC):

This already is a crop from the full frame. The old description stated:

A quick image of the well known Whirlpool Galaxy in a distance of 25 million lightyears. For this kind of objects some more focal length would be beneficial.