Seismic analysis of HD 43587Aa, a solar-like oscillator in a multiple system

¹ Institut d’Astrophysique Spatiale, CNRS, Université Paris Sud, UMR 8617, 91405 Orsay Cedex, France
e-mail: patrick.boumier@ias.u-psud.fr
² Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 Sydney, Australia
³ Astronomy Unit, Queen Mary, University of London, Mile End Road, London E1 4NS, UK
⁴ GEPI, Observatoire de Paris, CNRS UMR 8111, 92195 Meudon, France
⁵ Institut de Physique de Rennes, Université de Rennes 1, CNRS UMR 6251, 35042 Rennes, France
⁶ New Mexico State University, Department of Astronomy, PO Box 30001, MSC 4500, Las Cruces, NM, USA
⁷ School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
⁸ Laboratoire AIM, CEA/DSM-CNRS, Université Paris 7 Diderot, IRFU/Sap, Centre de Saclay, 91191 Gif-sur-Yvette, France
⁹ Astronomical Institute “Anton Pannekoek”, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
¹⁰ Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
¹¹ Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
¹² Universidad de La Laguna, Dpto de Astrofísica, 38206 La Laguna, Tenerife, Spain
¹³ Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d’Azur, BP 4229, 06304 Nice Cedex 4, France
¹⁴ Institut für Astrophysik, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
¹⁵ High Altitude Observatory, NCAR, PO Box 3000, Boulder, CO 80307, USA
¹⁶ Space Science Institute, 4750 Walnut Street Suite 205, Boulder, CO 80301, USA
¹⁷ LESIA, Observatoire de Paris, CNRS, Université Paris 6, Université Paris 7, UMR 8109, 92195 Meudon Cedex, France
¹⁸ Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 août, Bât. 5c, 4000 Liège, Belgium
¹⁹ INAF – Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate, Italy
²⁰ Depart. de Física Teórica e Experimental, Univ. Federal do Rio Grande do Norte, CEP 59072-970 Natal, RN, Brazil

Received: 12 August 2013
Accepted: 20 January 2014

Abstract

Context. The object HD 43587Aa is a G0V star observed during the 145-day LRa03 run of the COnvection, ROtation and planetary Transits space mission (CoRoT), for which complementary High Accuracy Radial velocity Planet Searcher (HARPS) spectra with S/N > 300 were also obtained. Its visual magnitude is 5.71, and its effective temperature is close to 5950 K. It has a known companion in a highly eccentric orbit and is also coupled with two more distant companions.

Aims. We undertake a preliminary investigation of the internal structure of HD 43587Aa.

Methods. We carried out a seismic analysis of the star, using maximum likelihood estimators and Markov chain Monte Carlo methods.

Results. We established the first table of the eigenmode frequencies, widths, and heights for HD 43587Aa. The star appears to have a mass and a radius slightly larger than the Sun, and is slightly older (5.6 Gyr). Two scenarios are suggested for the geometry of the star: either its inclination angle is very low, or the rotation velocity of the star is very low.

Conclusions. A more detailed study of the rotation and of the magnetic and chromospheric activity for this star is needed, and will be the subject of a further study. New high resolution spectrometric observations should be performed for at least several months in duration.