Oral Abstract

Oral Contribution (O0.4) Dirk van Dam ()

An Asymmetric Eclipser Seen Towards the Pre-Main Sequence Binary System V928 Tau

K2 observations of the weak-lined T Tauri binary V928 Tau A+B show the detection of a single, asymmetric eclipse which may be due to a previously unknown companion eclipsing one component of the binary at an intermediate separation (orbital period>66 days). Over an interval of about 9 hours, one component of the binary dims by around 60%, returning to its normal brightness about 5 hours later. From modeling of the eclipse shape we find evidence that the eclipsing companion may be surrounded by a disk or a vast ring system. A search in ground based archival data does not reveal any other convincing eclipses. V928 Tau is a previously known astrometric binary, with an orbital period inferred to be greater than 58 years (Schaefer et al. 2014). We present a new epoch of astrometry which can be used to further refine the orbit of the binary in the future, and place constraints on the possible orbital periods of the eclipsing companion.