A head-on collision with a black hole will likely produce a very noticeable explosion. Black holes don't just vacuum up all the matter around them silently. An

A head-on collision with a black hole will likely produce a very noticeable explosion. Black holes don't just vacuum up all the matter around them silently. Any matter falling into a black hole, not just the accretion disk, emits radiation. This radiation causes surrounding matter to expand outward, counteracting the gravity of the black hole. A black hole trying to eat an entire star at once will quickly exceed its Eddington limit [1] and most of the remaining matter will be blown away. [1] https://en.wikipedia.org/wiki/Eddington_luminosity https://en.wikipedia.org/wiki/Eddington_luminosity