New Silhouette Disks with Reflection Nebulae and Outflows in the Orion Nebula and M43

We report the detection of several new circumstellar disks seen in silhouettein the outskirts of the Orion nebula and M43, detected as part of our Halphasurvey of Orion with the HST/ACS. Several of the disks show bipolar reflectionnebulae, microjets, or temporal variability. Two disks in our sample are largeand particularly noteworthy: A nearly edge-on disk, d216-0939, is locatedseveral arcminutes northwest of M43 and resembles the famous HH30 disk/jetsystem in Taurus. It drives the 0.15 pc long bipolar outflow HH667, andexhibits a remarkable asymmetric reflection nebula. With a diameter of 1200 AU,it is as large as the giant edge-on silhouette disk d114-426 in the core of theOrion Nebula. The large disk d253-1536 is located in a binary system embeddedwithin an externally-ionized giant proplyd in M43. The disk exhibitsdistortions which we attribute to tidal interactions with a companion. Thebipolar jet HH668 emerges orthogonal to the disk, and a bow shock lies 54''south of this binary system along the outflow axis. Proper motions over 1.4 yrconfirm that these emission knots are moving away from d253-1536, with speedsas high as 330 km/s in the HH668 microjet, and slower motion farther from thestar.Comment: 19 pages, Fig 2 in color, accepted by A