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Name: NGC 3921, UGC 6823
Description: Interacting Galaxy
Position (J2000): RA 11h 51m 7.12s Dec 55° 4' 45.11"
Constellation: Ursa Major
Distance: 270 million light years
Visual magnitude: 12.4
Angular size: 2.1 x 1.3 arcmin
Field of view: 2.73 x 2.61 arcminutes
Orientation: North is 147.8° left of vertical
Image Credit: ESA/Hubble & NASA, Ack: Judy Schmidt
Release date: September 14, 2015
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It is known today that merging galaxies play a large role in the evolution of galaxies and the formation of elliptical galaxies in particular. However there are only a few merging systems close enough to be observed in depth. The pair of interacting galaxies picture seen here - known as NGC 3921 - is one of these systems.

NGC 3921 - found in the constellation of Ursa Major (The Great Bear) - is an interacting pair of disc galaxies in the late stages of its merger. Observations show that both of the galaxies involved were about the same mass and collided about 700 million years ago. You can see clearly in this image the disturbed morphology, tails and loops characteristic of a post-merger. This object was discovered by William Herschel on April 14, 1789

The clash of galaxies caused a rush of star formation and previous Hubble observations showed over 1000 bright, young star clusters bursting to life at the heart of the galaxy pair