The majority of these are thought to be first overtone ( e.g. X Sagittarii ) , or higher , pulsators .
Some unusual stars apparently pulsating in the fundamental mode also show this shape of light curve .
The majority of these are thought to be first overtone ( e.g. X Sagittarii ) , or higher , pulsators , although some unusual stars apparently pulsating in the fundamental mode also show this shape of light curve .