Circumstellar disks in Trapezium cluster (Vicente+, 2005)

To perform the diameter measurements we selected from the available Hubble Space Telescope (HST) images of the Orion Nebula (Bally et al.,2000AJ....119.2919B, the HST mosaicked "master" images of the Orion Nebula are accessible at http://casa.colorado.edu/~bally/HST/HST/master/) the one that provided the best contrast between the disk and the background nebula light. The available images are mosaic images from data acquired through filters F673N, F658N, F656N, F631N, F547N andF502N, under the general observer (GO) programs, GO 5085 (O'Dell &Wong, 1996, Cat. ) and GO 5469 (Bally et al., 1998AJ....116..293B;O'Dell, 1998AJ....115..263O). After quantitative comparisons we selected the Halpha image since it provided the best contrast and had the best signal-to-noise.(1 data file).