Distant galaxy fades 20-fold in just two decades, challenging how supermassive black holes evolve

An international team led by a researcher at the Chiba Institute of Technology has discovered an extremely rare phenomenon: a galaxy about 10 billion light-years away whose brightness dropped to one-twentieth of its original level in just 20 years. By combining multiwavelength observations with archival data spanning several decades, the researchers concluded that the fading was caused by a rapid decrease in the gas flowing into the supermassive black hole at the galaxy's center. The discove...