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First Results from the Hertzsprung SONG Telescope: Asteroseismology of the G5 Subgiant Star μ Herculis

Grundahl, F.; Andersen, M. Fredslund; Christensen-Dalsgaard, J.; Antoci, V.; Kjeldsen, H.; Handberg, R.; Houdek, G.; Bedding, T. R.; Pallé, P. L.; Jessen-Hansen, J.; Aguirre, V. Silva; White, T. R.; Frandsen, S.; Albrecht, S.; Andersen, M. I.; Arentoft, T.; Brogaard, K.; Chaplin, W. J.; Harpsøe, K.; Jørgensen, U. G.; Karovicova, I.; Karoff, C.; Rasmussen, P. Kjærgaard; Lund, M. N.; Lundkvist, M. Sloth; Skottfelt, J.; Norup Sørensen, A.; Tronsgaard, R. and Weiss, E. (2017). First Results from the Hertzsprung SONG Telescope: Asteroseismology of the G5 Subgiant Star μ Herculis. The Astrophysical Journal, 836(1), article no. 142.

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We report the first asteroseismic results obtained with the Hertzsprung Stellar Observations Network Group Telescope from an extensive high-precision radial-velocity observing campaign of the subgiant μ Herculis. The data set was collected during 215 nights in 2014 and 2015. We detected a total of 49 oscillation modes with l values from zero to three, including some l = 1 mixed modes. Based on the rotational splitting observed in l = 1 modes, we determine a rotational period of 52 days and a stellar inclination angle of 63°. The parameters obtained through modeling of the observed oscillation frequencies agree very well with independent observations and imply a stellar mass between 1.11 and 1.15 $M_{\odot}$ and an age of ${7.8}_{-0.4}^{+0.3}$ Gyr. Furthermore, the high-quality data allowed us to determine the acoustic depths of the He ii ionization layer and the base of the convection zone.

Item Type: Journal Item
Copyright Holders: 2017. The American Astronomical Society
ISSN: 1538-4357
Keywords: asteroseismology; spectrographic instrumentation; stellar observation; HD 161797; stellar oscillation
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Research Group: Centre for Electronic Imaging (CEI)
Item ID: 48803
Depositing User: Jesper Skottfelt
Date Deposited: 03 Mar 2017 11:12
Last Modified: 01 May 2019 21:21
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