Resolve the formation epoch of the candidate massive stars

Determine whether the candidate massive stars in Sh 2-205 originated during the earlier star-formation episode approximately 11–12 Myr ago or formed during the subsequent episode approximately 4–5 Myr ago.

Background

The paper interprets the ages of the candidate O- and B-type stars as broadly consistent with the earlier star-formation episode in Sh 2-205. However, stellar-age constraints and the inferred multi-episode history do not uniquely establish when each candidate massive star formed.

In particular, the authors state that a more recent origin during the later star-formation stage remains possible. Resolving the formation epoch is relevant to determining which massive stars powered the global expansion and whether the region’s feedback history involved one or multiple generations of massive stars.

References

While these stars likely originated during this earlier epoch, a more recent origin during the subsequent stage cannot be entirely ruled out.

— Star Formation in the H II Region Sh 2-205: 3D Morphology and Kinematics from Young Stars and Molecular Gas  (2608.16179 - Dong et al., 17 Aug 2026) in Section 5.2, “Multiple Episodes of Star Formation”