EPRV Asteroseismology of the K dwarfs GJ 570 A and GJ 783 A with ESPRESSO. Empirical mode-amplitude scaling in tension with 3D convection simulations
Abstract
Solar-like oscillations in K dwarfs have intrinsically low amplitudes, making them challenging to detect in space-based photometry. The advent of Extremely Precise Radial Velocity (EPRV) instrumentation enables Doppler asteroseismology in the mid-K regime, providing a new opportunity to test mode-excitation and damping physics. We investigate the scaling of oscillation amplitudes with stellar parameters and assess whether 3D surface convection simulations reproduce the observed amplitude behavior. High-cadence ESPRESSO radial-velocity time series were obtained over five and six consecutive nights for the K dwarfs GJ 570 A (K4 V) and GJ 783 A (K2.5 V), respectively. We identified oscillation modes from weighted power spectra and extracted them via sine-wave fitting following spectral deconvolution. Peak mode amplitudes were measured from heavily smoothed power spectra. For comparison, we performed 3D radiative-hydrodynamical simulations including excitation and damping-rate calculations. We measured 6 modes for GJ 570 A and 24 for GJ 783 A (ℓ=0-$2$, and ℓ=3 for GJ 783 A). The peak radial-mode amplitudes are 2.57 ± 0.52 cm s−1 and 4.90 ± 0.81 cm s−1, respectively. These results support a transition from an ∼(L/M)0.7 amplitude scaling to a steeper ∼(L/M)1.5 scaling, occurring near the G/K-dwarf boundary toward decreasing L/M. In contrast, 3D simulations predict an ∼(L/M)0.9 scaling for K dwarfs, revealing tension between observations and first-principles convection models. EPRV asteroseismology extends into the mid-K regime and exposes a steep mode-amplitude scaling that our 3D convection simulations do not reproduce. This discrepancy points to missing physics in our implementation of convection-pulsation coupling and/or limitations in the adopted modeling assumptions, motivating further theoretical investigation.
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BibTeX
@misc{campante2026eprv,
title = {{EPRV Asteroseismology of the K dwarfs GJ 570 A and GJ 783 A with ESPRESSO. Empirical mode-amplitude scaling in tension with 3D convection simulations}},
author = {T.L Campante and Y Zhou and Y Li and H Kjeldsen and R.R Costa and A.W Neitzel and J.H.C Martins and A.M Silva and V Adibekyan and J. Gomes da Silva and J.R Larsen and S.G Sousa and T.R Bedding and D Bossini and W.J Chaplin and E Corsaro and M.S Cunha and M Deal and D Huber and M.N Lund and M.S Lundkvist and T.S Metcalfe and M.J.P.F.G Monteiro and N.C Santos},
howpublished = {HAL},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.20985},
eprint = {2610.20985},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05842466v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - EPRV Asteroseismology of the K dwarfs GJ 570 A and GJ 783 A with ESPRESSO. Empirical mode-amplitude scaling in tension with 3D convection simulations
AU - T.L Campante
AU - Y Zhou
AU - Y Li
AU - H Kjeldsen
AU - R.R Costa
AU - A.W Neitzel
AU - J.H.C Martins
AU - A.M Silva
AU - V Adibekyan
AU - J. Gomes da Silva
AU - J.R Larsen
AU - S.G Sousa
AU - T.R Bedding
AU - D Bossini
AU - W.J Chaplin
AU - E Corsaro
AU - M.S Cunha
AU - M Deal
AU - D Huber
AU - M.N Lund
AU - M.S Lundkvist
AU - T.S Metcalfe
AU - M.J.P.F.G Monteiro
AU - N.C Santos
PY - 2026
DA - 2026/10/14
PB - HAL
DO - 10.48550/arxiv.2610.20985
UR - https://hal.science/hal-05842466v1
AB - Solar-like oscillations in K dwarfs have intrinsically low amplitudes, making them challenging to detect in space-based photometry. The advent of Extremely Precise Radial Velocity (EPRV) instrumentation enables Doppler asteroseismology in the mid-K regime, providing a new opportunity to test mode-excitation and damping physics. We investigate the scaling of oscillation amplitudes with stellar parameters and assess whether 3D surface convection simulations reproduce the observed amplitude behavior. High-cadence ESPRESSO radial-velocity time series were obtained over five and six consecutive nights for the K dwarfs GJ 570 A (K4 V) and GJ 783 A (K2.5 V), respectively. We identified oscillation modes from weighted power spectra and extracted them via sine-wave fitting following spectral deconvolution. Peak mode amplitudes were measured from heavily smoothed power spectra. For comparison, we performed 3D radiative-hydrodynamical simulations including excitation and damping-rate calculations. We measured 6 modes for GJ 570 A and 24 for GJ 783 A (ℓ=0-$2$, and ℓ=3 for GJ 783 A). The peak radial-mode amplitudes are 2.57 ± 0.52 cm s^−1 and 4.90 ± 0.81 cm s^−1, respectively. These results support a transition from an ∼(L/M)^0.7 amplitude scaling to a steeper ∼(L/M)^1.5 scaling, occurring near the G/K-dwarf boundary toward decreasing L/M. In contrast, 3D simulations predict an ∼(L/M)^0.9 scaling for K dwarfs, revealing tension between observations and first-principles convection models. EPRV asteroseismology extends into the mid-K regime and exposes a steep mode-amplitude scaling that our 3D convection simulations do not reproduce. This discrepancy points to missing physics in our implementation of convection-pulsation coupling and/or limitations in the adopted modeling assumptions, motivating further theoretical investigation.
ER -