New Supernovas

It is believed that one star goes supernova somewhere in the universe on average every single second and for the Milky Way galaxy this number is 3 stars every century. Humanity has only recently developed instruments like neutrino detectors that are sensitive enough to detect new supernovas. Neutrinos are emitted directly when the core collapses, so they arrive here earlier than the light. So if a neutrino detector picks up a supernova signal, they automatically send a message to various telescopes to watch that spot for the upcoming supernova. In fact, anyone can sign up to their early warning mailing list so you will get notified if they detect one. It's not reserved for just astronomers.