NEWLY DISCOVERED CANDIDATE WEAK-LINE T-TAURI STARS IN THE SURROUNDINGAREA OF THE TAURUS-AURIGA REGION

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 ba sis of the ROSAT All-Sky Survey Bright Source Catalog. Our surveyed re gion extends from 2(h)40(m) to 5(h)40(m) in right ascension and from 1 0 degrees to 40 degrees in declination. with the central part of Tauru s-Auriga (4(h) < alpha < 5(h), 15 degrees < delta < 34 degrees), accom plished by Wichmann et al. (1996), excluded. Within a sky coverage of about 10(3) square degrees, 219 X-ray sources fulfil the criteria for selecting program sources suggested by Neuhauser et al. (1995a), and 1 64 of these X-ray sources were found to have at least one optical coun terpart with E magnitude brighter than 16. Low-resolution spectroscopi c observation has been carried out in order to discard early type star s and galaxies from the sample, additional intermediate-resolution spe ctra of a sub-sample of 156 late type optical counterparts were obtain ed for spectral classification and for the calculation of the equivale nt width of H-alpha emission and LiI line absorption at 6707 Angstrom. Excluding 2 previously identified WTTS; a total of 75 new candidate W TTS and one possible classical T Tauri star have been discovered in ou r 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 Pl eiades.