Gravitational helioseismology?

Abstract

The magnitudes of the external gravitational perturbations associated with the normal modes of the Sun are evaluated to determine whether these solar oscillations could be observed with the proposed laser interferometer space antenna (LISA), a network of satellites designed to detect gravitational radiation. The modes of relevance to LISA—the $l=2\mathrm{}$, low-order $p$, $f$, and $g$ modes—have not been conclusively observed to date. We find that the energy in these modes must be greater than about ${10}^{30}$ ergs in order to be observable above the LISA detector noise. These mode energies are larger than generally expected, but are much smaller than the current observational upper limits. LISA may be confusion limited at the relevant frequencies due to the galactic background from short-period white dwarf binaries. Present estimates of the number of these binaries would require the solar modes to have energies above about ${10}^{33}$ ergs to be observable by LISA.