Black hole seen sucking star like it’s spaghetti

Astronomers at the European Southern Observatory observed a black hole shredding a star, a process called spaghettification, due to the black hole's gravitational force. This event, observed in the Arredinus constellation, was the closest of its kind. The study, published in the Monthly Notices of the Royal Astronomical Society, detailed the energy flares released as the star's material was consumed. Researchers used various wavelengths to study the event in detail. Scientists theorize that massive black holes exist in the Milky Way, but the risk of one affecting Earth is low.

How do astronomers detect the energy released when strands of material are sucked into a black hole?

What is the likelihood of a black hole in the Milky Way Galaxy affecting our sun and Earth?