Celestial hemisphere:  Northern  ·  Constellation: Coma Berenices (Com)  ·  Contains:  Mice Galaxy  ·  NGC 4676  ·  PGC 1911584  ·  PGC 43065  ·  The Mice
Arp 242, Gary Imm
Arp 242, Gary Imm
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Arp 242

Arp 242, Gary Imm
Arp 242, Gary Imm
Powered byPixInsight

Arp 242

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Description

This tiny distant object is a pair of colliding galaxies located 300 million light years away in the constellation of Coma Berenices at a declination of +31 degrees.  The pair of galaxies is nicknamed the "Mice".  This image is cropped from the original resolution to better show the galaxy detail.

The overall star stream length here is 4 arc-minutes in our apparent view, which corresponds to an actual distance of 500,000 light years.  Each galaxy disk is about 45,000 light years in diameter.

I find many different aspects of this object to be interesting. Unlike some objects in the Arp Catalogue, there is no question that these two colliding galaxies are gravitationally interacting. The long, extended star stream tails of each galaxy due to the galactic tides are fascinating. Equally amazing are the numerous color changes across the object, from yellow to blue, and then back to yellow and finally back to blue again. The dark lanes are unusually shaped. A wide star stream bridge connects the two galaxies.

Not that long ago, scientists didn't believe that stellar streams could be narrow, long and straight.  Those features were typically assumed to be some sort of jet instead.  Later, simulations showed that it is possible to obtain straight thin stellar streams.  I love here how the natures of these 2 tail streams are so much different - thin, straight and bright vs wide, curving and diffuse.

In my Galaxy Merger Collections, I have classified this one in the M3 category, which is galaxies that are are interacting and in the mid stage of a merger, with their disks touching, their cores in close contact, and significant star streams present.  That collection can be seen here.

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