a cluster of blue stars in the sky

This picture of the Pleiades, also known as M45, was taken from the centre of Copenhagen in bortle 9 skies. The bortle scale runs from 0-9 and estimates the impact city lights has on the visibility of the night sky. To get a good picture in these conditions a light pollution filter was used to amass a total of 300minute exposure time. M45 is one of the only deep sky objects that we can see with the naked eye from all ranges of the bortle scale. It's distance from Earth is a mere 440 light years This telescope and tracker was used: William Optics z61 + Skywatcher Star Adventurer