Notes. Breakdown of the stellar content of known Galactic young stellar aggregates (≤20 Myr; clusters and OB associations) ordered approximately by increasing age. Clusters/associations hosting sgB[e] stars given in bold. The upper pannel consists of clusters, the lower of OB associations (broken down where possible into constituent clusters), non-coeval aggregates (ages given in itallics) and the cluster W43, for which no age is given (but its youth is indicated by its associated GH ii region). NGC 3603 appears co-eval with the exception of the two BSGs Sher 23 and 25 which are suggestive of an older (~4 Myr) population. Regarding the GC cluster proper for simplicity we adopt the numbers of stars within the 2 coherent disc-like structures (Paumard et al. 2006) noting that a number of additional WR candidates (but no B[e] stars) have been identified in the surrounds. Classification of the Quintuplet OB supergiants is particularly difficult; via comparison to the Arches we reclassify LH099 as WN7-9ha but of the 84 stars Liermann et al. (2009) list as O stars we are unable to determine accurate spectral types and/or luminosity classes. Following the literature convention we restrict YHGs to spectral types A, F and G. Finally, we assign a tentative classification of LBV to V439 Cyg; a star with an uncertain history which Polcaro & Norci (1998) quote as being identified as respectively “Mira-like”, B3e, a carbon star, B0ep, B1.5 Ve and a candidate LBV over the last ~70 yrs.

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