Robo-AO Kepler Asteroseismic Survey. II. Do Stellar Companions Inhibit Stellar Oscillations?
Abstract
The Kepler Space Telescope observed over 15,000 stars for asteroseismic studies. Of these, 75% of dwarfs (and 8% of giants) were found to show anomalous behavior, such as suppressed oscillations (low amplitude) or no oscillations at all. The lack of solar-like oscillations may be a consequence of multiplicity, due to physical interactions with spectroscopic companions or due to the dilution of oscillation amplitudes from "wide" (AO detected; visual) or spectroscopic companions introducing contaminating flux. We present a search for stellar companions to 327 of the Kepler asteroseismic sample, which were expected to display solar-like oscillations. We used direct imaging with Robo-AO, which can resolve secondary sources at ~0."15, and followed up detected companions with Keck AO. Directly imaged companion systems with both separations of ≤0."5 and amplitude dilutions >10% all have anomalous primaries, suggesting these oscillation signals are diluted by a sufficient amount of excess flux. We also used the high-resolution spectrometer ESPaDOnS at the Canada–France–Hawai'i Telescope to search for spectroscopic binaries. We find tentative evidence for a higher fraction of spectroscopic binaries with high radial velocity scatter in anomalous systems, which would be consistent with previous results suggesting that oscillations are suppressed by tidal interactions in close eclipsing binaries.
Additional Information
© 2020 The American Astronomical Society. Received 2018 December 18; revised 2019 September 6; accepted 2019 October 8; published 2020 January 3. D.H. acknowledges support by the National Science Foundation (AST-1717000) and the National Aeronautics and Space Administration (80NSSC19K0597). C.B. acknowledges support from the Alfred P. Sloan Foundation. The Robo-AO instrument was developed with support from the National Science Foundation under grants AST-0906060, AST-0960343, and AST-1207891, IUCAA, the Mt. Cuba Astronomical Foundation, and by a gift from Samuel Oschin. The Robo-AO team thanks NSF and NOAO for making the Kitt Peak 2.1 m telescope available. We thank the observatory staff at Kitt Peak for their efforts to assist Robo-AO KP operations. The authors are honored to be permitted to conduct astronomical research on Iolkam Du'ag (Kitt Peak), a mountain with particular significance to the Tohono O'odham Nation. Robo-AO KP is a partnership between the California Institute of Technology, the University of Hawai'i, the University of North Carolina at Chapel Hill, the Inter-University Centre for Astronomy and Astrophysics (IUCAA) at Pune, India, and the National Central University, Taiwan. The Murty family feels very happy to have added a small value to this important project. Robo-AO KP is also supported by grants from the John Templeton Foundation and the Mt. Cuba Astronomical Foundation. Some data are based on observations at Kitt Peak National Observatory, National Optical Astronomy Observatory (NOAO Prop. ID: 15B-3001), which is operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Based on observations obtained at the Canada–France–Hawai'i Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawai'i. 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 Hawai'ian community. We are most fortunate to have the opportunity to conduct observations from this mountain. This research used the facilities of the Canadian Astronomy Data Centre operated by the National Research Council of Canada with the support of the Canadian Space Agency. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. This research has made use of NASA's Astrophysics Data System Bibliographic Services. We thank Dani Atkinson, Claire Moutou, Pascal Fouqué, and Nadine Manset for vital communications and important advice. We acknowledge the Exoplanet Follow-up Observing Program (ExoFOP) and Kepler Asteroseismic Science Operations Center (KASOC) databases, Python modules cv2 and pillow. Facilities: KPNO:2.1 m (Robo-AO) - , Keck:II (NIRC2-NGS) - , CFHT (ESPaDOnS). - Software: Astropy (Astropy Collaboration et al. 2013), Pyasl (https://pyastronomy.readthedocs.io/en/latest/), Libre-Esprit (Donati et al. 1997), Aperture Photometry Tool (APT) (Laher et al. 2012), DS9 (Smithsonian Astrophysical Observatory 2000; Joye & Mandel 2003).Attached Files
Published - Schonhut-Stasik_2020_ApJ_888_34.pdf
Submitted - 1910.03803.pdf
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Additional details
- Eprint ID
- 100000
- Resolver ID
- CaltechAUTHORS:20191121-145928839
- NSF
- AST-1717000
- NASA
- 80NSSC19K0597
- Alfred P. Sloan Foundation
- NSF
- AST-0906060
- NSF
- AST-0960343
- NSF
- AST-1207891
- Inter-University Centre for Astronomy and Astrophysics
- Mt. Cuba Astronomical Foundation
- Samuel Oschin
- John Templeton Foundation
- W. M. Keck Foundation
- Canadian Space Agency (CSA)
- Created
-
2019-11-21Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Astronomy Department, Division of Geological and Planetary Sciences (GPS)