What is the approximate lethal distance for the Physical Ejecta Shockwave from a supernova?

~1 Light Year

The Physical Ejecta Shockwave represents the final component of the initial outburst to arrive, consisting of high-energy particles and expanding stellar material ejected during the explosion. This wave carries tremendous kinetic energy. According to comparative data, the distance at which this shockwave becomes capable of stripping away a planetary atmosphere or completely eroding the surface is surprisingly close, estimated to be approximately 1 Light Year. This proximity is far closer than typical interstellar distances, meaning that while the light flash and radiation travel faster, the massive physical impact follows relatively soon after, though still potentially months or years later depending on the progenitor star's properties.