2025/05/22 by Caliskan, O., Uzundag, M., Kilic, M. +10 · 1 citation
#FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR)
paper · doi:10.48550/arxiv.2505.17177
We present extensive follow-up time-series photometry of WD J0049-2525, the most massive pulsating white dwarf currently known with T\rm eff = 13 020 \rm K and log\it g = 9.34 cm s-2. The discovery observations detected only two significant pulsation modes. Here, we report the detection of 13 significant pulsation modes ranging from 170 to 258 s based on 11 nights of observations with the New Technology Telescope, Gemini, and Apache Point Observatory telescopes. We use these 13 modes to perform asteroseismology and find that the best-fitting models (under the assumption of an ONe core composition) have M⋆ ≈ 1.29~M_\odot, surface hydrogen layer mass of log(M\rm H/M⋆) \lesssim -7.5, and a crystallized core fraction of >99%. An analysis of the period spacing also strongly suggests a very high mass. The asteroseismic distance derived is in good agreement with the distance provided by Gaia. We also find tentative evidence of a rotation period of 0.3 or 0.67 d. This analysis provides the first look at the interior of a ∼ 1.3~M\odot white dwarf.