Debris disks, exoplanets, and dynamical upheavals explored with HST/STIS

Monday 2 July, 15:30

High contrast direct imaging from both the ground and space continues to reveal new debris disks on solar system scales and evidence for planetary mass companions.  We present new HST/STIS coronagraphic observations of four M dwarfs that search for the scattered light component of dust initially detected with Herschel or ALMA.  We discovered one highly asymmetric dust disk around an M0 target in the 11 Myr-old Upper Sco association that could be a signature of a disk-planet perturbation.  Another target is Fomalhaut C (LP 876-10) where the data test for a highly eccentric disk resulting from dynamical interactions with Fomalhaut A and B.  In addition, we show deep STIS images of the HD 106906 planetary system that achieve higher signal-to-noise and a smaller inner working angle than previous HST/ACS optical observations.  The very extreme vertical and radial disk asymmetries of this 13 Myr-old Lower Centaurus-Crux debris disk indicate a recent dynamical upheaval involving a possible stellar flyby and/or the gas giant exoplanet  located over 700 AU away from the F5V central binary.  We also use the new data to test the hypothesis that HD 106906AB b is surrounded by a circumplanetary dust disk.


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