A&A Supplement series, Vol. 123, June I 1997, 329-352
Received March 14; accepted September 27, 1996
J. Krautter
-
R. Wichmann
- J.H.M.M. Schmitt
- J.M. Alcalá
- R. Neuhäuser
- L. Terranegra
Send offprint request: J. Krautter
Landessternwarte Königstuhl, D-69117 Heidelberg, Germany
Max-Planck-Institut für Extraterrestrische Physik, D-85740 Garching, Germany
Osservatorio Astronomico di Capodimonte, Via Moiariello 16,
I-80131 Napoli, Italy
Instituto Nacional de Astrofísica Optica y Electrónica, A.P. 51 y 216,
CP 72000, Puebla, México
We present first results obtained by a survey
of the Lupus star
forming region in search of
new T Tauri stars.
This study
has been performed on
the basis of deep pointed ROSAT observations in the Lupus dark clouds as well
as data from the ROSAT All-Sky-Survey in the surrounding,
less obscured regions.
Our survey covers an area of about
230 square degrees, located between 
and 
in right ascension and
between 
and 
in declination.
Identification of ROSAT All-Sky-Survey sources in this area by means
of optical spectroscopy revealed 89 TTauri stars,
86 of them ``weak-line" TTauri stars (WTTS)
not known from previous studies of
this region.
Our pointed ROSAT observations led to the identification
of 47 more TTauri stars, giving a total of 136 new TTauri stars.
The large area of our study, as compared with previous works,
allows us to study the spatial distribution of WTTS
in this star forming region on a large scale.
We find the new WTTS to be distributed
over the whole area of our survey, indicating that their spatial
distribution might extend well beyond our study area.
Contrary to the Lupus TTauri stars known prior to this study,
the WTTS discovered by the ROSAT All-Sky-Survey are not
clustered in the regions of highest extinction, i.e. the dark clouds.
keywords: stars: formation -- stars: pre-main sequence -- X-rays: stars -- surveys -- ISM: Lupus clouds