Kepler observations of the asteroseismic binary HD 176465

¹ Stellar Astrophysics Centre, Department of Physics and AstronomyAarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
e-mail: tim@phys.au.dk
² Institut für Astrophysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
³ Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
⁴ Department of Astronomy, The University of Tokyo, School of Science, 113-0033 Tokyo, Japan
⁵ Center for Space Science, NYUAD Institute, New York University Abu Dhabi, PO Box 129188, Abu Dhabi, UAE
⁶ Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006, Australia
⁷ School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK
⁸ Laboratoire AIM, CEA/DRF – CNRS – Univ. Paris Diderot – IRFU/SAp, Centre de Saclay, 91191 Gif-sur-Yvette Cedex, France
⁹ Oxford Astrophysics, University of Oxford, Keble Rd, Oxford OX1 3RH, UK
¹⁰ Tata Institute of Fundamental Research, Homi Bhabha Road, 400005 Mumbai, India
¹¹ Univ. Paris-Sud, Institut d’Astrophysique Spatiale, UMR 8617, CNRS, Bâtiment 121, 91405 Orsay Cedex, France
¹² Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Blvd de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France
¹³ Department of Astronomy, New Mexico State University, PO Box 30001, MSC 4500, Las Cruces, NM 88003-8001, USA
¹⁴ Apache Point Observatory, 2001 Apache Point Road, PO Box 59, Sunspot, NM 88349, USA
¹⁵ SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043, USA
¹⁶ Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, 8000 Aarhus C, Denmark
¹⁷ LESIA, CNRS, Université Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, 92195 Meudon Cedex, France
¹⁸ Space Science Institute, 4750 Walnut St. Suite 205, Boulder, CO 80301, USA
¹⁹ School of Physics and Astronomy, Raymond and Beverly Sackler, Faculty of Exact Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
²⁰ LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, 92 196 Meudon, France
²¹ Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
²² Universidad de La Laguna, Dpto. de Astrofísica, 38206 La Laguna, Tenerife, Spain

Received: 13 April 2016
Accepted: 16 August 2016

Abstract

Binary star systems are important for understanding stellar structure and evolution, and are especially useful when oscillations can be detected and analysed with asteroseismology. However, only four systems are known in which solar-like oscillations are detected in both components. Here, we analyse the fifth such system, HD 176465, which was observed by Kepler. We carefully analysed the system’s power spectrum to measure individual mode frequencies, adapting our methods where necessary to accommodate the fact that both stars oscillate in a similar frequency range. We also modelled the two stars independently by fitting stellar models to the frequencies and complementaryparameters. We are able to cleanly separate the oscillation modes in both systems. The stellar models produce compatible ages and initial compositions for the stars, as is expected from their common and contemporaneous origin. Combining the individual ages, the system is about 3.0 ± 0.5 Gyr old. The two components of HD 176465 are young physically-similar oscillating solar analogues, the first such system to be found, and provide important constraints for stellar evolution and asteroseismology.