CaltechAUTHORS
Published June 2019 | Version Accepted Version + Published
Journal Article Open

Spectroscopic confirmation of the binary nature of the hybrid pulsator KIC 5709664 found with the frequency modulation method

Creators

  • 1. ROR icon Eötvös Loránd University
  • 2. ROR icon Konkoly Observatory
  • 3. ROR icon University of Sydney
  • 4. ROR icon Aarhus University
  • 5. ROR icon Research Centre for Astronomy and Earth Sciences
  • 6. ROR icon University of Szeged
  • 7. ROR icon Thüringer Landessternwarte Tautenburg
  • 8. ROR icon New Mexico State University
  • 9. ROR icon Keele University
  • 10. ROR icon Radboud University Nijmegen
  • 11. ROR icon University of California, Berkeley
  • 12. ROR icon Massachusetts Institute of Technology
  • 13. ROR icon California Institute of Technology

Abstract

We started a program to search for companions around hybrid δ Sct/γ Dor stars with the frequency modulation method using Kepler data. Our best candidate was KIC 5709664, where we could identify Fourier peaks with sidelobes, suggesting binary orbital motion. We determined the orbital parameters with the phase modulation method and took spectroscopic measurements to confirm unambiguously the binary nature with radial velocities. The spectra show that the object is a double-lined spectroscopic binary, and we determined the orbital solutions from the radial velocity curve fit. The parameters from the phase modulation method and the radial velocity fits are in good agreement. We combined a radial velocity and phase modulation approach to determine the orbital parameters as accurately as possible. We determined that the pulsator is a hybrid δ Sct/γ Dor star in an eccentric binary system with an orbital period of ∼95 d and an eccentricity of 0.55. The measured mass ratio is 0.67. We analysed the pulsation content and extracted 38 frequencies with amplitudes greater than 20 μmag. At low frequencies, we found broad power excesses which are likely attributed to spots on the rotating surface of the lower mass component. We inferred rotation periods of 0.56 and 2.53 d for the primary and secondary, respectively.

Additional Information

© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) Accepted 2019 March 21. Received 2019 March 21; in original form 2018 June 28. This project has been supported by the Hungarian NKFI Grants K-113117, K-115709, K-119517, and KH-130372 of the Hungarian National Research, Development and Innovation Office. AD was supported by the ÚNKP-18-4 New National Excellence Program of the Ministry of Human Capacities and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences. AD would like to thank the City of Szombathely for support under Agreement No. 67.177-21/2016. SJM is a DECRA fellow supported by the Australian Research Council (grant number DE180101104). This project has been supported by the Lendület Program of the Hungarian Academy of Sciences, project No. LP2018-7/2018. SzM has been supported by the Premium Postdoctoral Research Program of the Hungarian Academy of Sciences. HL was supported by the DFG grant LE 1102/3-1. Based on observations obtained with the APO 3.5-m telescope, which is owned and operated by the Astrophysical Research Consortium. IRAF is distributed by the National Optical Astronomy Observatories, which are operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

Attached Files

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Accepted Version - 1904.03490.pdf

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Additional details

Identifiers

Eprint ID
97408
Resolver ID
CaltechAUTHORS:20190725-125943357

Related works

Describes
https://arxiv.org/abs/1904.03490 (URL)

Funding

National Research, Development and Innovation Office (Hungary)
K-113117
National Research, Development, and Innovation Office (Hungary)
K-115709
National Research, Development, and Innovation Office (Hungary)
K-119517
National Research, Development, and Innovation Office (Hungary)
KH-130372
Ministry of Human Capacities (Hungary)
ÚNKP-18-4
Hungarian Academy of Sciences
LP2018-7/2018
City of Szombathely
67.177-21/2016
Australian Research Council
DE180101104
Deutsche Forschungsgemeinschaft (DFG)
LE 1102/3-1
NSF

Dates

Created
2019-08-01
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field