A Predicted Great Dimming of T Tauri: Has it Begun?

Abstract

The optical star in the T Tauri triple system is the prototype of young Sun-like stars in our galaxy. This complex and dynamic system has evidence for misaligned disks and outflows, and molecular material in a circumbinary ring that obscures the southern infrared binary, T Tau South. Observations by members of the American Association of Variable Star Observers show that T Tau North, the optical star, has dimmed by up to ∼2 mag in the visual over the course of the past decade. The dimming across the B , V , R , and I bands has a color character typical of changes in interstellar medium extinction, suggesting an increase in obscuration along the line of sight to T Tau North. Material associated with the circumbinary ring around T Tau South has been predicted to occult the optical star via wide-scale orbital motion of the system. Through analysis of the geometrical configuration and motion of dust structures in the system, it seems that a great dimming of T Tau North by line-of-sight material associated with the T Tau South binary has, in fact, begun. Based on the extent and motion of the circumbinary ring material associated with the southern binary, T Tau North will likely experience dimming events for decades to come and may disappear entirely from the optical sky as the densest midplane region of the ring traverses our line of sight.

Keywords

• Classical T Tauri stars
• Circumstellar disks
• T Tauri stars