Arp 104, also known as Keenan’s System, is a pair of luminous interacting galaxies consisting of NGC 5216, an elliptical, and NGC 5218, a disturbed disk galaxy and joined by a stellar bridge. This bridge was created when the two galaxies passed by each other, their mutual gravity pulling the gas out. The stream is about 150,000 light years in length. Other tidal streams at the opposite sides of the galaxies are also visible. The interacting pair of galaxies is located in the constellation Ursa Major at a distance of about 17 million light-years. The other prominent galaxy in the middle of the image is NGC 5205.
Arp 104 (NGC 5216 & 5218) (right) and NGC 5205 (middle)
Telescope: 16″ f3.75 Dream Scope
Camera: FLI ML16803
Mount: ASA DDM85
Exposure: 7 hours (50x300s L + 3x11x300s RGB)
Date: December 2019
Location: Southern Alps, France
Detail of NGC 5205 and Arp 104
Bart Delsaert - Astrophotography 