Mutual events in the trans-Neptunian belt

Unlike binary systems in the inner Solar System, the trans-Neptunian binaries have a wide range of characteristics, from a large primary with a small moon to (near) equal-sized binaries with primary and secondary having similar sizes, and from close/contact binaries if the distance between the components is small/inexistent to ultra-wide binaries with a very large distance between the components. A powerful technique to learn about binary systems is the observation of mutual events between the system's components. A mutual event happens when the secondary is passing in front or behind the primary. This technique has been utilized for decades to characterize binary main-belt asteroids, near-Earth objects, and Jupiter's Trojans to improve the satellite's orbit computation and the estimations of the size, shape, density, and albedo for each component. However, successful events have been detected in the trans-Neptunian belt for only two systems: Pluto-Charon and Sila-Nunam. We have identified 10 additional trans-Neptunian binaries which are undergoing/will undergo mutual events seasons. In order to successfully predict and observe mutual events, we obtained some ground-based lightcurves for most of these systems over the past few years. Lightcurves will be used to extract some basic characteristics of the systems, such as rotational period, and constraints for the shapes. These characteristics will then be used as inputs for lightcurve modeling to predict as accurately as possible the mutual events seasons and the individual mutual events. Ultimately, our lightcurve modeling will be put to the test by observing some mutual events.