Dueling Galaxies NGC 3729 and 3718 in Ursa Major
Galaxy NGC 3718, on the right in this image, is entry #214 in the Arp catalog of Peculiar Gaxaxies published in 1966.  The most striking feature of NGC
3718 is the "warped" dust lane running through the stellar bulge. This dust lane is visible because the galaxy is almost edge-on to our line of sight.  The shape
seen here, however, differs dramatically from other edge-on galaxies like NGC 891 or NGC 4565.  Because we are seeing the galaxy from the side, the curve
of the dust filaments at the top and bottom of the galaxy are not simply "spiral" arms, but rather "warping" of the galaxy's arms above and below the plane of
the galaxy.  Why?  Gravitational interaction with
NGC 3729, only 150,000 light years apart, is contributing to this distortion.  NGC 3729, in the upper left of
this image, is a barred spiral galaxy.  NGC 3718 is a  Syfert type 1.9 galaxy with an active galactic nucleus.  Both of these galaxies lie at a distance of about 50
million light years in the constellation Ursa Major.


Move the cursor over the image to see evidence of gravitational interaction with faint intergalactic strands of stars sheared from NGC 3718.

This image combined 155 minutes of luminance exposures unbinned with 60 minutes of red, 45 minutes green and 60 minutes of blue exposures, binned 2x2.  
Total exposure time was over 5 hours, split between two nights.  An ST10XME camera was used through a Meade 12" LX200R and an AP reducer at the
Hidden Lake Observatory.
Music:  Duelin' Banjos
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