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

Journal Article · Fri Feb 10 00:00:00 EST 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/836/1/142· OSTI ID:22869351

Grundahl, F.; Andersen, M. Fredslund; Christensen-Dalsgaard, J.; Antoci, V.; Kjeldsen, H.; Handberg, R.; Houdek, G.; Bedding, T. R.; Jessen-Hansen, J.; Aguirre, V. Silva; White, T. R.; Frandsen, S.; Albrecht, S.; Arentoft, T.; Brogaard, K.; Chaplin, W. J. ^[1]; Pallé, P. L. ^[2]; Andersen, M. I. ^[3]; Harpsøe, K.; others, and

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1. Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus (Denmark)
2. Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)
3. Niels Bohr Institute, University of Copenhagen, Juliane Maries vej 30, DK-2100 Copenhagen (Denmark)

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 {sub ⊙} and an age of 7.8{sub −0.4}{sup +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.

• OSTI ID: 22869351
• Journal Information: Astrophysical Journal, Vol. 836, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCURACY
COMPUTERIZED SIMULATION
CONVECTION
DATA ANALYSIS
INCLINATION
IONIZATION
OSCILLATION MODES
OSCILLATIONS
RADIAL VELOCITY
STARS
TELESCOPES