What celestial phenomenon must observers await first following Betelgeuse's core-collapse supernova?

Answer

The arrival of high-energy neutrinos

The overwhelming majority of energy released during the core collapse is carried away by neutrinos, which travel at speeds nearly identical to the speed of light and arrive before the visible light signal.

What celestial phenomenon must observers await first following Betelgeuse's core-collapse supernova?
astronomyBeetlejuicestarsupernova