Twenty Years of Watching One Galaxy, and It Made Less Sense

Blazars are galaxies with a jet aimed almost directly at us, and they flicker across every part of the spectrum at once. Almost everything we think we know about them comes from short observing campaigns just a handful of days, every year or two, in one narrow band of energy. A Polish and German team has now done the opposite, following a single blazar for nearly twenty years with two orbiting observatories and in two observations from 2012 they found something in the spectrum that nobody had pr