NGC 5216 and 5218 - Keenan's System in Ursa Major

Exploring the Sloan Digital Sky Survey (3)

NGC 5216 and 5218 - Keenan's System in Ursa Major

NGC 5216 (top) and NGC 5218 (below) have a debris trail between them
that is
22,000 light years in length. P. C. Keenan noted this double galaxy in
1935 and it was later noted by observers at the Lick and Palomar
observatories. NGC 5218 also has a countertide - a fingerlike
extension pointing in a different direction to the debris trail. This
is a typical structure of interacting double galaxy systems.

http://www.martin-nicholson.info/exp...ss/ngc5216.htm

Martin Nicholson, Daventry, England.
http://www.martin-nicholson.info/1/1a.htm

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