A Lithium-Survey for Pre-Main Sequence Stars in the
Upper Scorpius OB Association
Th. Preibisch, E. Guenther, H. Zinnecker, M. Sterzik, S. Frink,
& S. Röser
Astronomy & Astrophysics, 333, 619, (1998)
We present the results of an intermediate resolution
spectroscopic survey for pre-main sequence (PMS) stars
in the Upper Scorpius
OB association. In a 160 square-degree area
we were able to identify 39 new PMS stars
by follow up observations of X-ray selected stars with the
multi object spectrograph FLAIR at the UK Schmidt Telescope.
We also investigated
the completeness of our X-ray selected sample by observing
more than 100 stars that were not detected as X-ray sources,
but have proper motions indicating membership to Upper Sco.
While the new X-ray selected PMS stars with known proper
motions have kinematics consistent with membership, none of the
X-ray quiet proper motions candidates is a PMS star.
We conclude that our X-ray selected sample of PMS stars
seems to be rather complete. For stars in the magnitude
interval 11.5 <= B <= 13.5 we derive a
conservative lower limit of 75% completeness.
Retrieve compressed Postscript file (172kB)
of the paper
Back to the publication list
or to my homepage .