Issue |
Astron. Astrophys. Suppl. Ser.
Volume 132, Number 2, October II 1998
|
|
---|---|---|
Page(s) | 173 - 179 | |
DOI | https://doi.org/10.1051/aas:1998288 | |
Published online | 15 October 1998 |
Newly discovered candidate weak-line T Tauri stars in the surrounding area of the Taurus-Auriga region *,**
Beijing Astronomical Observatory, Chinese Academy of Sciences, Beijing 100080, China
Send offprint request to: J.Z. Li
Received:
5
May
1997
Accepted:
14
April
1998
We present results of an extensive search for weak-line T Tauri
stars (WTTS) in the outskirts of the Taurus-Auriga molecular cloud
on the basis of the ROSAT All-Sky Survey Bright Source Catalog. Our
surveyed region extends from 2h40m to
5h40m in right ascension and from 10° to
40° in declination, with the central part of
Taurus-Auriga (4 5h,
15
34°), accomplished by Wichmann et al. (1996), excluded. Within a sky coverage of about 103
square degrees, 219 X-ray sources fulfil the criteria for selecting
program sources suggested by Neuhäuser et al. (1995a), and 164 of these X-ray sources were found to have
at least one optical counterpart with E magnitude brighter than
16. Low-resolution spectroscopic observation has been carried out in
order to discard early type stars and galaxies from the sample,
additional intermediate-resolution spectra of a sub-sample of 156
late type optical counterparts were obtained for spectral
classification and for the calculation of the equivalent width of
H
emission and LiI line absorption at 6707 Å. Excluding
2 previously identified WTTS, a total of 75 new candidate WTTS and
one possible classical T Tauri star have been discovered in our
study. The majority of the newly found Li-rich optical counterparts
are believed to be PMS stars rather than ZAMS stars as those of the
Pleiades.
Key words: stars: formation / stars: pre-main sequence / X-ray: stars / surveys
© European Southern Observatory (ESO), 1998