Poster Presentation

Modeling the impacts of radiative feedback from a red supergiant on circumstellar dust [Cancelled]

Author(s): Bao Truong (Korea Astronomy and Space Science Institute, University of Science and Technology) Le Ngoc Tram (Max-Planck-Institut für Radioastronomie) Thiem Hoang (Korea Astronomy and Space Science Institute, University of Science and Technology)

Presenter: Gia Bao Truong le (Korea Astronomy and Space Science Institute (KASI); University of Science and Technology (UST))

Circumstellar dust is formed and evolved within the envelope of evolved stars. The extinction of stellar light by circumstellar dust is vital for interpreting RSG/AGB observations. Nevertheless, circumstellar dust properties are not well understood. Modern understanding of dust evolution suggests intense stellar radiation can change the dust properties across the circumstellar envelope through the RAdiative Torque Disruption (RAT-D) mechanism. In this paper, we study the impacts of RAT-D on the grain size distribution (GSD) of circumstellar dust and model its effects on photometric observations of α Orionis. Due to the RAT-D effects, large grains formed in the dust formation zone are disrupted into smaller species of size a < 0.5 μm. Using the GSD constrained by the RAT-D effects, we model the visual extinction of background stars and Betelgeuse. We find that the extinction decreases at near-UV, optical, and infrared wavelengths while increasing at far-UV wavelengths. The resulting flux potentially reproduces the observation from the near-UV to the near-IR range. Our results can be used to explain dust extinction and photometric observations toward other RSG/AGB stars.