What distinguished the explosion observed in SN 2023zkd?
A significant second brightening occurring months after the initial flash.
The event designated SN 2023zkd presented a unique temporal profile that set it apart from standard supernova models. After the initial, expected bright flash associated with the supernova explosion, observations revealed a pronounced and luminous second flare several months later. Furthermore, archival data showed that the progenitor star had actually been slowly increasing its luminosity over the four years preceding the main blast. The current interpretation links this sequence of events to the star existing in a close binary orbit with a black hole. The star likely shed a large, thick disk of material while interacting with its companion. The initial explosion then struck this pre-existing disk, heating it intensely and causing the delayed, luminous flare observed months later, providing evidence of pre-supernova binary interaction.
