The Bullseye galaxy: a ring galaxy with a resonant twist – Big Think
Across the Universe, galaxies come in four major types.Credit: ESA/Euclid/Euclid Consortium/NASA, CEA Paris-Saclay; Processing: J.-C. Cuillandre, E. Bertin, G. AnselmiSpiral and ellipticals describe most common, normal galaxies.Many small or interacting galaxies become irregularly shaped.But rarely, a ring shape emerges.Only 1-in-10,000 galaxies are rings: defined by circular collections of stars beyond the main galactic body.Rings appear in many stages of formation, with one leading theory for their creation.When a fast-moving galaxy “punches through” another’s center, ripples of matter propagate outward.They trigger new star-formation, while removing gas from the galaxy’s center.At late times, a stable, settled-down ring structure emerges.But the newly discovered Bullseye galaxy, LEDA 1313424, represents a “ring” that’s still forming.A small, dwarf galaxy “punched through” the larger galaxy’s center, creating gaseous ripples.Many (at least nine) independent rings have been serially identified, radiating outward.The small galaxy is blue, indicating newly-forming stars from the collision.The main galaxy, too, is littered with streams of young blue stars.The central pile-up of rings can be teased apart owing to Hubble’s incredible optical views.These rings obey a resonant pattern: confirming a longstanding “resonant ring” prediction.With NASA’s Nancy Roman telescope coming, the Bullseye galaxy should soon be joined by many similar discoveries.Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words.
Source: https://bigthink.com/starts-with-a-bang/bullseye-galaxy-ring-twist/
