Black holes are famous for being ravenous eaters, but they do not eat everything that falls toward them. A small portion of material gets shot back out in powerful jets of hot gas, called plasma, that can wreak havoc on their surroundings. Along the way, this plasma somehow gets energized enough to strongly radiate light, forming two bright columns along the black hole’s axis of rotation.
In June 2015, V404 Cygni underwent dramatic brightening for about two weeks, as it devoured material that it had stripped off an orbiting companion star. Violent red flashes, lasting just fractions of a second, were observed during the flare-up — one of the brightest black hole outbursts in recent years.