A Hubble Space Telescope study of two HII regions in NGC 6822

We report on the study of the Hubble V and Hubble X H II regions in NGC 682 2 with the Hubble Space Telescope employing emission-line and stellar filte rs. Calibration was made for both data sets, providing magnitudes for the s tars and surface brightnesses for the nebulae. The forms of these H II regi ons are shown to be decidedly more complex than revealed by ground-based im ages, both having bright cores within more extended emission. The four OB a ssociations within the images are shown to have ages of 5-10 million years. We conclude that the H II regions are sufficiently optically thick to be u sed as ultraviolet photon counters and hence indicators of the star formati on rate.