Letter to the Editor

Butterfly diagram of a Sun-like star observed using asteroseismology

¹ Division of Sciences, New York University Abu Dhabi, UAE
e-mail: mb6215@nyu.edu
² Center for Space Science, NYUAD Institute, Abu Dhabi, UAE
³ Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Boulevard de l’Observatoire, Nice Cedex 4 CS 34229, 06304, France
⁴ Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, Aarhus C, 8000, Denmark
⁵ IRAP (Institut de Recherche en Astrophysique et Planétologie), Université de Toulouse, CNRS, CNES, UPS, Toulouse 31400, France
⁶ Max-Planck-Institut für Sonnensystemforschung, Göttingen Germany
⁷ Institut für Astrophysik, Georg-August-Universität Göttingen, Göttingen, Germany
⁸ New York University, NY 10012, USA

Received: 14 September 2018
Accepted: 19 October 2018

Abstract

Stellar magnetic fields are poorly understood, but are known to be important for stellar evolution and exoplanet habitability. They drive stellar activity, which is the main observational constraint on theoretical models for magnetic field generation and evolution. Starspots are the main manifestation of the magnetic fields at the stellar surface. In this study we measured the variation in their latitude with time, called a butterfly diagram in the solar case, for the solar analogue HD 173701 (KIC 8006161). To this end, we used Kepler data to combine starspot rotation rates at different epochs and the asteroseismically determined latitudinal variation in the stellar rotation rates. We observe a clear variation in the latitude of the starspots. It is the first time such a diagram has been constructed using asteroseismic data.