Looking Up: The Trouble With Triples

May 1, 2017

Three galaxies in one field of view!
Credit Image Credit: ESO, INAF-VST, OmegaCAM; Acknowledgement: OmegaCen, Astro-WISE, Kapteyn I. / nasa.gov

This week on Looking Up Hal takes us on a trip to a galactic triplet.

If you are a baseball fan, you likely are very excited by triple plays. If you love burgers, a triple with everything sounds delicious. But if you are interested in looking up this spring, you can see the biggest triple out there – the Leo triple galaxy cluster!

The constellation of Leo the Lion is high in the Southern Colorado sky right now. If you aim a telescope at the area sort of behind the back legs (I’m trying to be dignified here), you can see a remarkable sight – three lovely galaxies, all in the same field of view. The first two are Messier object 65, a lovely spiral galaxy, and Messier object 66, another spiral galaxy with a weird and unknown radio source coming from its center. The last member of the triplet is another galaxy, which Messier did not catalogue, known by the number NGC 3628. This galaxy is an edge-on spiral, and its prominent dust lanes are visible. These dust lanes are rather distorted, likely from the gravitational effects of its two neighbor galaxies. In fact, M66 also shows significant alteration in its spiral arms due to the same gravity distortion. Only M65 appears to be largely unaffected by the neighbors, though a recent uptick in star formation just may be related to trouble in the neighborhood, galactically speaking. So, if you are going to visit the Leo Triplet, watch out for gravity bullies.

If you’d like to take a closer look at the Leo Triplet or any of the wonderful and amazing things in the sky, please visit CSASTRO.org for a link to information on our monthly meetings and our free public star parties! 

This is Hal Bidlack for the Colorado Springs Astronomical Society, telling you to keep looking up, Southern Colorado!