First Quadruple-Double Radio Galaxy Discovered

Astronomers have discovered the first 'quadruple-double' radio galaxy, where the central supermassive black hole launched powerful jets on four separate occasions. The galaxy, J023721.13−010528.5, is located about 4 billion light-years away and spans 3.9 million light-years. High-resolution observations from GMRT, MeerKAT, and VLA reveal four nested pairs of hotspots, each representing a distinct outburst. The outbursts occurred at different epochs, with the youngest being around 4.5 million years old and the oldest around 20.5 million years old. The discovery challenges previous understanding of radio galaxy activity and suggests that giant S-shaped radio galaxies may be the best places to find more of these rare multi-episode systems.