Lorenzo Sironi is an astrophysicist interested in the most energetic and powerful phenomena of the universe—involving the explosive death of massive stars and the presence of neutron stars or black holes. He studies the radiation signatures of such objects, trying to unveil the physical processes acting in these extreme environments. He focuses in particular on the acceleration of particles to highly relativistic energies and on the generation or dissipation of magnetic fields. He graduated from the Scuola Normale of Pisa in Italy in 2006, and got his doctorate in astrophysical sciences from Princeton University in 2011. He is currently a NASA Einstein Postdoctoral Fellow at Harvard University.