Detection of a Bipolar Flow Associated With UX Ori: An Intermediate-Mass Pre-Main Sequence Star

Previous studies of intermediate mass (2–10 M⊙) pre-main sequence stars have suggested that the early phases (t ≤ 105 yr) of accretion are accompanied by a significant return of material to the ISM via strong bipolar outflows (Levreault 1988). Recent studies of a number of Herbig Ae/Be stars with large and variable obscuration by circumstellar dust and Polarimetric data suggesting that we view the systems through the disks indicate that accretion continues to at least 106 yrs (Bibo & The 1991; Grinin et al. 1991; Welty et al. 1992; Perez et al. 1993; Graham 1992). The 1992 deep optical minimum, when circumstellar dust provided “a natural coronagraph” of the isolated Herbig A2e star, UX Ori, has provided a unique opportunity to determine whether bipolar emission line regions suggestive, in an edge-on system, of bipolar flows, are detectable in older PMS stars.