Astrophysics Seminar: Don Dixon, Vanderbilt University


Location: 184 Nieuwland Science Hall (View on map )

TESS Light Curve Variability of White Dwarf Component Binaries in the AGGC

Don Dixon
Graduate Student
Vanderbilt University

t has been observationally estimated that a quarter of the white dwarf main-sequence (WDMS) binary population evolved from progenitor systems of interacting binaries. This finding suggests characterizing large samples of WDMS binaries will yield insight into the outcomes into binary evolution, particularly case B/C mass transfer and common envelope evolution. The APOGEE-GALEX-Gaia Catalog (AGGC) was constructed leveraging data from the large scale spectroscopic and photometric surveys alluded to in its name and identifies 3414 systems that have UV excess consistent with a hot white dwarf companion. Out of the complete catalog 1806 have SED inferred white dwarf radii < 25 earth radii,  defining a more reliable subset of the catalog. To better understand the connection between the rotational and binary properties of short period WDMS binaries we utilize TESS light curve data for the reliable partition of the AGGC to identify signatures of spot modulation, ellipsoidal variations, and eclipses. In this preliminary work we find periodic light curve variability throughout the AGGC, especially for systems consistent with the binary sequence and sub-subgiants.  We also find a strong correlation between ΔRVmax, projected rotational velocity and light curve periodicity, which serves as evidence of orbital synchronization and coupled binary and rotational evolutionary histories.

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