Ejection of a Low-Mass Star in a Young Stellar System in Taurus

We present the analysis of high angular resolution Very Large Array radio observations, made at 11 epochs over the last 20 years, of the multiple system T Tauri. One of the sources (Sb) in the system has moved at moderate speed (5-10 km s-1) on an apparently elliptical orbit during the first 15 yr of observations, but after a close (<2 AU) encounter with the source Sa, it appears to have accelerated westward to about 20 km s-1 in the last few years. Such a dramatic orbital change most probably indicates that Sb has just suffered an ejection—which would be the first such event ever detected. Whether Sb will ultimately stay on a highly elliptical bound orbit or whether it will leave the system altogether will be known with about 5 more years of observations.