Detailed Characterization of Heartbeat Stars and Their Tidally Excited Oscillations
Abstract
Heartbeat stars are a class of eccentric binary stars with short-period orbits and characteristic "heartbeat" signals in their light curves at periastron, caused primarily by tidal distortion. In many heartbeat stars, tidally excited oscillations can be observed throughout the orbit, with frequencies at exact integer multiples of the orbital frequency. Here, we characterize the tidally excited oscillations in the heartbeat stars KIC 6117415, KIC 11494130, and KIC 5790807. Using Kepler light curves and radial-velocity measurements, we first model the heartbeat stars using the binary modeling software ELLC, including gravity darkening, limb darkening, Doppler boosting, and reflection. We then conduct a frequency analysis to determine the amplitudes and frequencies of the tidally excited oscillations. Finally, we apply tidal theories to stellar structure models of each system to determine whether chance resonances can be responsible for the observed tidally excited oscillations, or whether a resonance-locking process is at work. We find that resonance locking is likely occurring in KIC 11494130, but not in KIC 6117415 or KIC 5790807.
Additional Information
© 2020 The American Astronomical Society. Received 2020 July 8; revised 2020 August 26; accepted 2020 August 31; published 2020 November 9. S.J.C. would like to thank Susan Mullally for aiding in light-curve processing, as well as Kevin Burdge and Erik Petigura for assistance with light-curve modeling. This research is funded in part by a Heising-Simons Foundation 2018 Scialog grant (#2018-1036), an Innovator Grant from The Rose Hills Foundation, and the Sloan Foundation through grant FG-2018-10515. K.H. and J.F. acknowledge support through a NASA ADAP grant (NNX17AF02G). The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.Attached Files
Published - Cheng_2020_ApJ_903_122.pdf
Accepted Version - 2009.01851.pdf
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Additional details
- Eprint ID
- 105432
- Resolver ID
- CaltechAUTHORS:20200916-113003457
- 2018-1036
- Heising-Simons Foundation
- Rose Hills Foundation
- FG-2018-10515
- Alfred P. Sloan Foundation
- NNX17AF02G
- NASA
- Created
-
2020-09-16Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Astronomy Department, TAPIR, Walter Burke Institute for Theoretical Physics