Cool Stars 14 - Submitted Abstract # 251
This version created on 05 October 2006

A New Candidate Post-T Tauri Group at d ~ 90  pc Associated with 32
Ori


Eric Mamajek, Harvard-Smithsonian Center for Astrophysics

Within the past decade, several new, nearby young stellar associations
within ~100  pc have been identified (e.g.  TW Hya, eta Cha, epsilon
Cha, Tuc-Hor, beta Pic, AB Dor groups) which are helping shed light on
circumstellar disk evolution and the recent star-formation history in
the solar neighborhood.  Here I present the evidence for the existence
of a new, nearby, candidate post-T Tauri (~25 Myr-old) group at d ~ 90
pc associated with the B5V+B7V binary 32 Orionis.  The group appears
to be rather poor, but it does appear to account for part of the
population of "isolated" Li-rich, X-ray-bright ROSAT All-Sky Survey
stars in northern Orion (e.g.  RX J0520.0+0612, RX J0520.5+0616, RX
J0523.7+0652) whose large proper motions clearly reject them from
belonging to the more distant Ori OB1 subgroups (d ~ 400  pc).

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