Same as → periodic.
periodically variable supergiant (PVSG)
abarqul-e vartande-ye dowreyi
Fr.: supergéante variable périodiquement
A variable → supergiant star with typical periods of the order of 10 to 100 days and amplitudes less than a few tenths of a magnitude. PVSGs are thought to be pulsating → g modes, caused by a density inversion, arising from an → opacity bump, most likely from Fe, H, and/or He.