Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 1, 2013 | Published + Accepted Version
Journal Article Open

Tidally induced oscillations and orbital decay in compact triple-star systems


We investigate the nature of tidal effects in compact triple-star systems. The hierarchical structure of a triple system produces tidal forcing at high frequencies unobtainable in binary systems, allowing for the tidal excitation of high-frequency p-modes in the stellar components. The tidal forcing exists even for circular, aligned and synchronized systems. We calculate the magnitude and frequencies of three-body tidal forcing on the central primary star for circular and coplanar orbits, and we estimate the amplitude of the tidally excited oscillation modes. We also calculate the secular orbital changes induced by the tidally excited modes and show that they can cause significant orbital decay. During certain phases of stellar evolution, the tidal dissipation may be greatly enhanced by resonance locking. We then compare our theory to observations of HD 181068, which is a hierarchical triply eclipsing star system in the Kepler field of view. The observed oscillation frequencies in HD 181068 can be naturally explained by three-body tidal effects. We then compare the observed oscillation amplitudes and phases in HD 181068 to our predictions, finding mostly good agreement. Finally, we discuss the past and future evolution of compact triple systems like HD 181068.

Additional Information

© 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2012 November 27. Received 2012 October 17. We thank Dong Lai and Dan Tamayo for useful discussions. JF acknowledges the hospitality (autumn 2011) of the Kavli Institute for Theoretical Physics at UCSB (funded by the NSF through Grant 11-Astro11F-0016) where part of the work was carried out. This project has been supported by NSF grants AST-1008245 and AST-1211061, NASA grants NNX12AF85G and NNX10AP19G, the Hungarian OTKA Grants K76816, K83790 and MB08C 81013 and the 'Lendület-2009' Young Researchers Programme of the Hungarian Academy of Sciences. Part of the research leading to these results has received funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007--2013)/ERC grant agreement no. 227224 (PROSPERITY). AD gratefully acknowledges financial support from the Magyary Zoltán Public Foundation. AD was supported by the Hungarian Eötvös fellowship. AD has been supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences. LLK wishes to thank support from the European Community's Seventh Framework Programme (FP7/2007--2013) under grant agreement no. 269194. The Kepler Team and the Kepler Guest Observer Office are recognized for helping to make the mission and these data possible.

Attached Files

Published - sts511.pdf

Accepted Version - 1211.6814.pdf


Files (4.0 MB)
Name Size Download all
2.0 MB Preview Download
2.0 MB Preview Download

Additional details

August 19, 2023
October 20, 2023