Number of lethal astrophysical transient events (solid red line) in the past 500 Myr as a function of distance from the Galactic center. The individual contributions of SGRBs (solid green line), LGRBs (solid yellow line) and SNe (solid orange line) are shown. The surface number density of TPs around M stars (dashed dark blue line) and around FGK stars (dashed light blue line) are reported (left vertical axis). The vertical solid black line at 8 kpc marks the position of the Solar System at which the total number of lethal events (predominantly LGRBs) is ∼1.3.