Many of the most famous galaxies are praised for their complexity, like the sprawling halo of the Sombrero galaxy and the seemingly never-ending stretch of space Andromeda, along with her estimated one trillion stars, occupies. Sometimes, it's important to recognize and appreciate "peaceful galaxies:" the ones that aren't overtly large, bright or chaotic, but are still significant in their own special way.
This galaxy, dubbed NGC 5972, certainly appears to be one of them. That is, until you take a look at the galaxy at non-optical wavelengths. With our eyes, we see a galaxy remarkable only for its bright central nucleus and the long filaments of material, called tidal tails, that extend away from it like interstellar tendrils of light. Interestingly, from our vantage point, the overall structure of the filaments holds an uncanny resemblance to a double-helix. Only on an unbelievably large-scale.
Astronomers didn't know how extensive they would wind up being until 2012, when the galaxy was probed as a part of Galaxy Zoo’s "Voorwerpje project," which aimed to study active galaxies known to harbor large quantities of ionized material. Instead of this material congregating within the primary galaxy's confines (where the majority of star formation activity takes place), the bulk of this material surrounds the galaxy as a whole — oftentimes tripling the galaxy's size. (One notable example is Hanny's Voorwerp)
With NGC 5972, the ionized, looped material encompassing the galaxy is so abundant, the filter designed to capture an image at the proper wavelengths was unable to capture all of it in one shot (seen below).
"Here’s a combination of the Hα image (red) and [O III] (green) data, with the caution that neither has been corrected for the contribution of starlight yet. The image is about 40 arcseconds across, which translates to 75,000 light-years at the distance of NGC 5972," the Galaxy Zoo team remarked.
They also noted that it has "another nucleus with a loop of ionized gas pushing outward (this time lined up with the giant radio source), twisted braids of gas like a 30,000-light-year double helix, and dramatically twisted filaments of dust suggesting that the galaxy still hasn’t settled down from a strong disturbance."
Learn more about the Voorwerpje project here, from the folks at 'UniverseToday.'