Eclipses of young stars by dust fragments in protoplanetary disks are the main reason for stochastic variability in the luminosity of UX Ori stars. In analyses and modeling of these kinds of eclipses, the star is often treated as a point light source. This approach is fully justified in the case of hot stars in this family, since the sublimation radius for the dust in their circumstellar disk is much greater than the star’s radius. This approach may not apply to the case of cold stars, since the evaporation zone for the circumstellar dust is close to the star. Here it is shown that accounting for the finite size of the radiation source leads to a change in the shape of a color track on a “color-magnitude” diagram. Calculations for the star V695 Per simultaneously illustrate the variability of the brightness of UX Ori and AA Tau stars for the coldest currently known star of this type.

Original languageEnglish
Pages (from-to)41-47
Number of pages7
JournalAstrophysics
Volume62
Issue number1
DOIs
StatePublished - 1 Mar 2019

    Research areas

  • UX Ori stars: the star V695 Per: circumstellar extinction

    Scopus subject areas

  • Astronomy and Astrophysics

ID: 87473614