Main Belt Comets and Asteroid Systems Seen with the Extreme AO

Dr. Bin Yang

ESO

Abstract:

In this talk, I will focus on the two hottest topics in the solar system studies: 1) Main-belt comets (MBCs) and 2) extreme adaptive optics (AO) observations of asteroid systems. MBCs are a recently discovered class of volatile-containing objects with comet-like morphology and asteroid-like orbits. MBCs may represent the closest reservoir of comets and may have been an important source of water for the Earth’s oceans. However, MBCs are challenging targets to study due to their small sizes and relatively large distances from the Sun and the Earth. In 2015, a number of weakly active short-period comets in the vicinity of the Earth were identified that might originate in the main asteroid belt, known as near Earth Main-belt comets (NEMBCs). I will present our pioneer study of a NEMBC, which serves as the best test bed to verify specific predictions of early solar system models and how volatile materials reached Earth.

The recently commissioned Spectro-Polarimetric High-contrast Exoplanet Research instrument (SPHERE), with its superb sensitivity and spatial resolution, offers unprecedented opportunity for detecting and characterizing multiple asteroid systems. Asteroids with satellites are of particular importance because their formation mechanisms, accretional and collisional processes, are critical in planet formation and evolution. I will talk about the comparative spectroscopic and direct imaging study of two large multiple asteroid systems: (93) Minerva and (130) Elektra with SPHERE. Lastly, I will briefly talk about the latest SPHERE observation of an ultra-fast moving binary asteroid, 1999 KW4.