Why are blazars important for astronomers to study?
A blazar is a galaxy whose central supermassive black hole emits a powerful jet of high-velocity particles aimed almost directly at Earth.
Actually speaking, Blazars are generally associated with super massive black holes at the centre of big galaxies. The thing that makes them important for the study of astronomy is that they are "THE HULK" of all the phenomenon occurring in the universe, meaning that they are the most energetic phenomenon of the extragalactic universe. These super energetic process can help give astronomers a better understanding of the interstellar space.