  Pulsating hot B subdwarf (sdB) stars, which are core-He burning objects, are
one of the showcases of asteroseismology. Thanks to the combination of rich
pulsation spectra and state-of-the-art modeling tools it is possible to tightly
constrain fundamental parameters such as the stellar mass. There are on the
contrary very few hotter sdO pulsators, which are in a more advanced
evolutionary stage. Some of them are identified in Globular Clusters (GCs), but
they are extremely rare in the field. Recently, it was suggested that PB8783,
one of the very first sdB pulsators discovered in 1997, may in fact be an
unrecognized hot sdO star with very similar properties to the GC pulsators. We
present here new very high-quality spectroscopy of PB8783 as well as an
asteroseismic analysis of the pulsator and answer the question: is PB 8783 the
first sdO star suitable for asteroseismic modeling?
