Bolometric corrections of stellar oscillation amplitudes as observed by the Kepler, CoRoT, and TESS missions. (arXiv:1907.12557v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Lund_M/0/1/0/all/0/1">Mikkel N. Lund</a>
A better understanding of the amplitudes of stellar oscillation modes and
surface granulation is essential for improving theories of mode physics and the
properties of the outer convection zone of solar-like stars. A proper
prediction of these amplitudes is also essential for appraising the
detectability of solar-like oscillations for asteroseismic analysis.
Comparisons with models, or between different photometric missions, are enabled
by applying a bolometric correction, which converts mission-specific amplitudes
to their corresponding bolometric (full light) values. We derive the bolometric
correction factor for amplitudes of radial oscillation modes and surface
granulation as observed by the Kepler, CoRoT, and TESS missions. The
calculations are done assuming a stellar spectrum given by a black-body as well
as by synthetic spectral flux densities from 1D model atmospheres. We derive a
power-law and polynomial relations for the bolometric correction as a function
of temperature from the black-body approximation and evaluate the deviations
from adopting a more realistic spectrum. Across the full temperature range from
4000 – 7500 K, the amplitudes from TESS are in the black-body approximation
predicted to be a factor ~0.83 – 0.84 times those observed by Kepler. We find
that using more realistic flux spectra over the black-body approximation can
change the bolometric correction by as much as ~30% at the lowest temperatures,
but with a change typically within ~5 – 10% around a $T_{rm eff}$ of 5500 –
6000 K. We find that after $T_{rm eff}$, the bolometric correction most
strongly depends on [M/H], which could have an impact on reported metallicity
dependencies of amplitudes reported in the literature.
A better understanding of the amplitudes of stellar oscillation modes and
surface granulation is essential for improving theories of mode physics and the
properties of the outer convection zone of solar-like stars. A proper
prediction of these amplitudes is also essential for appraising the
detectability of solar-like oscillations for asteroseismic analysis.
Comparisons with models, or between different photometric missions, are enabled
by applying a bolometric correction, which converts mission-specific amplitudes
to their corresponding bolometric (full light) values. We derive the bolometric
correction factor for amplitudes of radial oscillation modes and surface
granulation as observed by the Kepler, CoRoT, and TESS missions. The
calculations are done assuming a stellar spectrum given by a black-body as well
as by synthetic spectral flux densities from 1D model atmospheres. We derive a
power-law and polynomial relations for the bolometric correction as a function
of temperature from the black-body approximation and evaluate the deviations
from adopting a more realistic spectrum. Across the full temperature range from
4000 – 7500 K, the amplitudes from TESS are in the black-body approximation
predicted to be a factor ~0.83 – 0.84 times those observed by Kepler. We find
that using more realistic flux spectra over the black-body approximation can
change the bolometric correction by as much as ~30% at the lowest temperatures,
but with a change typically within ~5 – 10% around a $T_{rm eff}$ of 5500 –
6000 K. We find that after $T_{rm eff}$, the bolometric correction most
strongly depends on [M/H], which could have an impact on reported metallicity
dependencies of amplitudes reported in the literature.
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