While it is necessary to use quite large telescope under dark sky to see its spiral structure by eye (Earl of Rosse, who discovered it in 1845, used a telescope with 1.8 m bronze primary mirror), spirals are revealed quite easily when the galaxy is captured with sensitive digital camera. This makes the galaxy quite popular among astro-photographers.

But the M51 image presented above is definitely not “just another M51 image”. Fabian Neyer combined almost 147 hours of exposures taken with G3-16200 CCD camera and C3-61000 CMOS camera on the TEC 140 APO refractor to create it. The result is an incredibly deep and detailed image, revealing not only the galaxy structure in unprecedented details, but also many background galaxies, dark interstellar clouds belonging to our own galaxy and especially hydrogen cloud, shown in deep red Hα line to the left of the M51, which probably originated from the merger of both galaxies. Capturing of this extremely faint cloud is a rare feat (it is simply missing on majority of M51 portraits).