Blooming Insights on Stellar Evolution and Stellar Interiors from White Dwarf Seismology

Pulsating White Dwarf stars tell us about their internal chemical makeup. Stellar interiors encapsulate their evolution history, and can reveal insights to their evolutionary pasts. In this talk, I will discuss two examples of how changing the structure of a white dwarfs from prior evolutionary processes impacts their ensuing pulsation properties.

First, I will discuss how white dwarf seismology can detect the presence/absence of ²²Ne. The amount of ²²Ne in a white dwarf is tied to its birth metallicity. Neglecting ²²Ne in white dwarf models may be ignoring the impact of the stars’ initial metallicity.

Second, I will discuss how certain trapped modes may constrain the ¹²C(α,γ)¹⁶O reaction rate. This reaction occurs during core helium burning in stellar evolution, and is of fundamental importance in nuclear astrophysics; the rate of this reaction determines the C/O ratio of our universe. We find certain signature g-mode periods to distinguish the ¹²C(α,γ)¹⁶O reaction rate probability distribution function, even under the inclusion of overshooting in the stars’ evolution history. Thus, white dwarf seismology may further constrain the ¹²C(α,γ)¹⁶O reaction rate, and overall be a promising avenue to reveal details of stellar interiors and their evolutionary pasts.