The HST survey of the Orion Nebula region

The HST Treasury Program on the Orion Nebula Cluster has been recently completed (May 2005). Using 104 orbits of HST time we have imaged a field {∼ }1/6 of a square degree nearly centered on the Trapezium stars. The survey, made with ACS, WFPC2 and NICMOS-Camera 3 in parallel, has imaged this cornerstone region with unprecedented sensitivity (23-24 mag), dynamic range (∼12 mag), spatial resolution (50mas), and wide spectral coverage (9 filters from U to H). We have assembled the richest, most accurate and unbiased dataset of stellar photometry for pre-main-sequence objects ever obtained, an essential tool for understanding of the star formation process in regions dominated by massive OB stars.