| Time：1150225 (Wed.) 14:20~16:20 Speaker：Dr. 歐柏昇 (OU, Po-Sheng) 中央研究院天文及天文物理研究所/Institute of Astronomy and Astrophysics, Academia Sinica Title：Why Do Stars Turn Red? Abstract：We revisit the long-standing question in stellar astrophysics: Why do post–main-sequence stars evolve into red giants (RGs) or red supergiants (RSGs)? We first compare stellar evolution models that reach the RG/RSG phase with those that remain blue and show that envelope expansion follows a refined “mirror principle.” Building on this result, we construct steady-state envelope models to identify the physically realizable configurations of stellar envelopes. These solutions verify the refined mirror principle and clarify the physical nature of the RG/RSG phase as a limiting configuration of stellar structure. In this talk, I will present our main discoveries and discuss how we overcame the key difficulties in addressing this long-standing problem. Place：S101, Gongguan Campus, NTNU |
