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

Rappaport S. A., Kurtz D. W., Handler G., Jones D., Nelson L. A., Saio H., ...More

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, vol.503, no.1, pp.254-269, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 503 Issue: 1
  • Publication Date: 2021
  • Doi Number: 10.1093/mnras/stab336
  • Journal Name: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Applied Science & Technology Source, Communication Abstracts, INSPEC, Metadex, zbMATH, DIALNET, Civil Engineering Abstracts
  • Page Numbers: pp.254-269
  • Keywords: binaries: general, stars: individual: TIC 63328020, stars: oscillations
  • Çanakkale Onsekiz Mart University Affiliated: Yes

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 pulsatormodel, the primary oscillation is identified as a sectoral dipole mode with l = 1, vertical bar m vertical bar = 1. We find the pulsating star to have M-1 similar or equal to 2.5M(circle dot), R-1 similar or equal to 3R(circle dot), and T-eff, 1 similar or equal to 8000 K, while the secondary has M-2 similar or equal to 1.1M(circle dot), R-2 similar or equal to 2R(circle dot), and T-eff, 2 similar or equal to 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.