# PB 8783: the first sdO star suitable for asteroseismic modeling?

## TL;DR

This paper investigates whether PB 8783, a pulsating hot star previously classified as sdB, is actually an sdO star suitable for detailed asteroseismic modeling, which could expand understanding of hotter, more evolved pulsators.

## Contribution

The study provides new high-quality spectroscopy and asteroseismic analysis to determine the true nature of PB 8783, potentially identifying it as the first sdO star suitable for asteroseismic modeling.

## Key findings

- Spectroscopic data suggest PB 8783 is an sdO star.
- Asteroseismic analysis supports its classification as sdO.
- Potential for PB 8783 to serve as a new asteroseismic target.

## Abstract

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?