http://www.skyandtelescope.com/astro...stellar-comet/

Wow, this is fascinating...

"... an object swept up just a week ago by observers using the PanSTARRS 1 telescope atop Haleakala on Maui has an extreme orbit — it's on a hyperbolic trajectory that doesn't appear to be bound to the Sun. Preliminary findings, published earlier today [10/25/2017] by the International Astronomical Union's Minor Planet Center (MPC), suggest that we are witnessing a comet that escaped from another star."