UGCA 180 and Friend

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Joined: Thu Jul 17, 2014 8:20 pm
Location: Green Valley, Arizona

UGCA 180 and Friend

Post by Russ.Carpenter »

This is my latest effort in the parade of peculiar galaxies visible from Chile. The Astrobin link is


UGCA 180 and Friend

Here is another unsung marvel from the Southern Hemisphere. UGCA 180 (the lower galaxy) and IC 2507 (the upper galaxy) are a close galaxy pair—but what strange galaxies they are!

This image is part of my on-going investigation of peculiar galaxies in the Southern Hemisphere. I believe this is the first time this galaxy pair has been imaged and published by an amateur.

Officially, UGCA 180 is an emission-line galaxy, because of its strong radiation from Ha. Its morphology is more interesting. It might seem like a stretch, but this twisted little galaxy is classified as a peculiar barred spiral. Peculiar, indeed.

IC 2507 is also an emission-line galaxy. Its morphology is a “Magellanic irregular galaxy,” which seems to me like an elaborate way of confessing that astronomers don’t really know what’s going on. The intriguing thing is that galaxies of this kind show no trace of spiral arms, but are nevertheless capable of triggering star formation. My image plainly shows star formation, with the knots of blue color.

This is not an easy pair to image. UGCA is only 2.1 arc minutes wide, while IC 2507 is a mere 1.6 arc minutes.

Both UGCA 180 and IC 2507 meet the definition of a peculiar galaxy in The Catalog of Southern Peculiar Galaxies and Associations, by Halton Arp and Barry Madore. They both fall under Category 16—irregular or disturbed galaxies, and Category 23—close pairs and triples.

Tech Notes for ASA 500/3.6:
ASA Newtonian, 500 mm aperture, 1900mm focal length, F3.6
FLI Proline 16803, 9 mm pixel, 4096 X 4096
ASA DDM85 equatorial mount
Processing with PixInsight, StarTools, and Affinity Photo
UGCA180 Final Small.jpg
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