Astronomer Prof Tim Bedding from @Sydney_Science @Sydney_Physics tells me: "Looking at the last few decades on the AAVSO web site (below), I would guess this is a result of the different periodicities happening to produce a deeper-than-usual minimum." #Betelgeuse #astronomy 1/2 pic.twitter.com/MCPuaedQe1

— Marcus Strom (@strom_m) December 8, 2019