CTIO and WFPC2 photometry in NGC 6822

The four-band WFPC2 photometry is used to derive Teff and E(B-V). H-R diagrams are constructed for the OB associations included in our fields.

These show that 10Myr old populations are present in OB 9 and OB 6, while more recent star formation have occurred in OB 8, OB 13, OB 15, and OB 7. Two particularly interesting H II regions, Hubble V and Hubble X, are included in our fields. The luminous massive stars that power these bright H II regions (H{alpha} luminosity several times that of the Orion nebula), could be resolved even in their dense cores thanks to the HST spatial resolution.