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

Nathan Smith·John Bally·Daniel Licht·Josh Walawender
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Abstract

We report the detection of several new circumstellar disks seen in silhouette in the outskirts of the Orion nebula and M43, detected as part of our Halpha survey of Orion with the HST/ACS. Several of the disks show bipolar reflection nebulae, microjets, or temporal variability. Two disks in our sample are large and particularly noteworthy: A nearly edge-on disk, d216-0939, is located several arcminutes northwest of M43 and resembles the famous HH30 disk/jet system in Taurus. It drives the 0.15 pc long bipolar outflow HH667, and exhibits 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 the Orion Nebula. The large disk d253-1536 is located in a binary system embedded within an externally-ionized giant proplyd in M43. The disk exhibits distortions which we attribute to tidal interactions with a companion. The bipolar 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 yr confirm that these emission knots are moving away from d253-1536, with speeds as high as 330 km/s in the HH668 microjet, and slower motion farther from the star.

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Nathan Smith, John Bally, Daniel Licht, Josh Walawender. 2004-10-06. New Silhouette Disks with Reflection Nebulae and Outflows in the Orion Nebula and M43. https://doi.org/10.1086/426567

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