The Near-Sun Dust Environment as Seen by Parker Solar Probe
Résumé
Over the last two years, and six near-Sun encounter orbits, the Parker Solar Probe spacecraft has provided the first in-situ observations of interplanetary dust closer than ~0.3 AU from the Sun. Dust is detected by the FIELDS instrument via impact ionization and subsequent perturbations to the plasma environment close to the spacecraft. FIELDS observations yield count rates, impact amplitudes, and impact directionality information. Interpreting these data to arrive at new understanding of dust dynamics of the inner heliosphere requires combining state-of-the-art modeling and theory with detailed FIELDS instrument knowledge. In this talk, we describe recent results related to the near-Sun dust environment, including: bounding the location and rate of beta-meteoroid production, the interaction of debris streams with near-Sun dust, the density of near-circular dust near the Sun, hints of dust sublimation close to the Sun, and the effects of instrument operation on dust impact detection. The Parker Solar Probe FIELDS data provide an in-situ window into stellar processing of dust in the near-Sun plasma environment, and we are beginning to understand what we see.