Strange glowing 'bow-and-arrow' structure may be a giant cosmic shock wave created by a supersonic galaxy collision

A red wisp of gas on a starry background.

A bizarre radio galaxy discovered by a citizen scientist has left astronomers puzzled, revealing a never-before-seen "bow-and-arrow" structure that could offer rare insight into how galaxies are reshaped by colossal shock waves as they plunge through galaxy clusters.

Named RAD-BAARG (short for Radio Bow-And-Arrow Radio Galaxy), the object spans nearly 1.8 million light-years across, making it almost 18 times wider than the Milky Way. Its unusual structure was first identified by a citizen scientist participating in the RAD@home Astronomy Collaboratory, which allows volunteers to review telescope data and flag unusual features that might otherwise be missed.