Oscillations in the Sun with SONG: Setting the scale for asteroseismic investigations

Fredslund A. M.; Pallé, P. L.; Jessen-Hansen, J.; Wang, K.; Grundahl, F.; Bedding, T. R.; Roca Cortes, T.; Yu, J.; Mathur, S.; Gacia, R. A.; Arentoft, T.; Régulo, C.; Tronsgaard, R.; Kjeldsen, H.; Christensen-Dalsgaard, J.
Bibliographical reference

Astronomy and Astrophysics, Volume 623, id.L9, 4 pp.

Advertised on:
3
2019
Number of authors
15
IAC number of authors
5
Citations
11
Refereed citations
10
Description
Context. We present the first high-cadence multiwavelength radial-velocity observations of the Sun-as-a-star, carried out during 57 consecutive days using the stellar échelle spectrograph at the Hertzsprung SONG Telescope operating at the Teide Observatory. Aims: Our aim was to produce a high-quality data set and reference values for the global helioseismic parameters νmax, ⊙ and Δν⊙ of the solar p-modes using the SONG instrument. The obtained data set or the inferred values should then be used when the scaling relations are applied to other stars showing solar-like oscillations observed with SONG or similar instruments. Methods: We used different approaches to analyse the power spectrum of the time series to determine νmax, ⊙: simple Gaussian fitting and heavy smoothing of the power spectrum. We determined Δν⊙ using the method of autocorrelation of the power spectrum. The amplitude per radial mode was determined using the method described in Kjeldsen et al. (2008, ApJ, 682, 1370). Results: We found the following values for the solar oscillations using the SONG spectrograph: νmax, ⊙ = 3141 ± 12 μHz, Δν⊙ = 134.98 ± 0.04 μHz, and an average amplitude of the strongest radial modes of 16.6 ± 0.4 cm s-1. These values are consistent with previous measurements with other techniques. Based on observations made at the Hertzsprung SONG telescope operated at the Spanish Observatorio del Teide on the island of Tenerife by the Aarhus and Copenhagen Universities and by the Instituto de Astrofísica de Canarias.
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The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur