AA << reveal a new phenomenon dubbed the "rocking shadow" effect that describes how disks in forming planetary systems are oriented, and how they move around their host star. The effect also gives clues as to how they might evolve with time. >>
<< Protoplanetary disks are often thought to be shaped like dinner plates—thin, round and flat. However, recent telescope images from the Atacama Large Millimeter/Submillimeter Array (ALMA) show that this is not always the case. Some of the disks seen by ALMA have shadows on them, where the part of the disk closest to the star blocks some of the stellar light and casts a shadow onto the outer part of the disk. From this shadow pattern, it can be inferred that the inner part of the disk is oriented completely differently to the outer part, in what is called a broken disk. >>️️
<< As the inner disk moved through the gravitational pull of the central star, the shadow it cast moved across the outer disk. But instead of the shadow pattern moving around the disk like a clock-hand as expected, it rocked back and forth with a see-saw-like motion. So although the inside disk kept turning in the same direction, its shadow looked like it was rocking forwards and backwards. >>
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Examining rocking shadows in protoplanetary disks. Royal Astronomical Society. Jul 15, 2022.
Rocking shadows in broken
circumbinary discs.
The National Astronomy Meeting (NAM) 2022. The University of Warwick, 11th. Jul 15, 2022.
keywords: gst, astro, shadow, rocking shadow, broken disc
