A tidally tilted sectoral dipole pulsation mode in the eclipsing binary TIC 63328020

Abstract

We report the discovery of the third tidally tilted pulsator, TIC 63328020. Observations with the TESS satellite reveal binary eclipses with an orbital period of 1.1057 d, and $\delta$ Scuti-type pulsations with a mode frequency of 21.09533 d${}^{-1}$. This pulsation exhibits a septuplet of orbital sidelobes as well as a harmonic quintuplet. Using the oblique pulsator model, the primary oscillation is identified as a sectoral dipole mode with $l=1,|m|=1$. We find the pulsating star to have $M_1\simeq 2.5{\mathrm{M}}_{\odot }$, $R_1\simeq 3{\mathrm{R}}_{\odot }$, and $T_{\mathrm{eff},1}\simeq 8000$ K, while the secondary has $M_2\simeq 1.1{\mathrm{M}}_{\odot }$, $R_2\simeq 2{\mathrm{R}}_{\odot }$, and $T_{\mathrm{eff},2}\simeq 5600$ K. Both stars appear to be close to filling their respective Roche lobes. The properties of this binary as well as the tidally tilted pulsations differ from the previous two tidally tilted pulsators, HD74423 and CO Cam, in important ways. We also study the prior history of this system with binary evolution models and conclude that extensive mass transfer has occurred from the current secondary to the primary.

16 pages, 12 figures, and 8 tables

References in corpus (10)

• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• Galactic Reddening in 3D from Stellar Photometry - An Improved Map
• Observations of Doppler Boosting in Kepler Lightcurves
• Spectral models for solar-scaled and alpha-enhanced stellar populations
• Population Synthesis of Cataclysmic Variables: I. Inclusion of Detailed Nuclear Evolution
• Catalogue and Properties of δ Scuti Stars in Binaries
• Eclipsing binary stars with a $\delta$ Scuti component
• The single-sided pulsator CO~Camelopardalis
• Tidally Trapped Pulsations in Binary Stars
• Spectroscopy of hot Gamma Doradus and A-F hybrid Kepler candidates close to the hot border of the Delta Scuti instability strip

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• Mass transfer and tidally tilted pulsation in the Algol-type system TZ Dra
• Tidally Tilted Pulsations in HD 265435, a subdwarf B Star with a Close White Dwarf Companion
• Discovery of Delta Scuti variables in eclipsing binary systems II.Southern TESS field search
• TIC 435850195: The Second Tri-Axial, Tidally Tilted Pulsator