Featured Image: A Search for Spiral-Arm-Driving Planets

This image, captured with the Very Large Telescope SPHERE adaptive optics in Chile, reveals the large-scale spiral arms visible in the MWC 758 protoplanetary disk, located less than 500 light-years away. Such arms are thought to be triggered by one of two mechanisms: gravitational instability, or a companion orbiting within the disk. A team of scientists led by Bin Ren (The Johns Hopkins University) has recently used observations of these arms over a decade-long baseline to track the speed of rotation of the arms. Since companion-driven arms corotate with their drivers, this exercise which could reveal the location of a planetary-mass, unseen companion that drives the arms. Ren and collaborators find that the most likely location for such a planet to orbit in this disk is at 89 AU, just outside of the visible spiral arms. For more information, check out the article below.


Bin Ren et al 2018 ApJL 857 L9. doi:10.3847/2041-8213/aab7f5