Progenitor Model of SN 1987A Based on the Slow Merger Scenario

Understand

Even after elaborate investigations for 30 years, we still do not know well how the progenitor of SN 1987A has evolved.

• To explain unusual red-to-blue evolution, previous studies suggest that in a red giant stage either the increase of surface He abundance or the envelope mass was necessary.
• It is usually supposed that the He enhancement is caused by the rotational mixing, and the mass increase is by a binary merger.
• Thus, we have investigated these scenarios thoroughly.