1998AJ....115.2074B

We present the initial results of a deep CCD survey for very low mass pre-main-sequence (PMS) stars in selected fields of the Taurus molecular cloud complex. The results reported herein span a little over half a square degree in the dark clouds L1495, L1529, L1551, and B209. Our survey is complete down to I_C ∼ 19 at (R - I)_C ∼ 2.5, which enables us to probe well below the hydrogen burning limit at 1-2 Myr. From follow-up spectroscopic observations we have identified nine new low-mass T Tauri stars (TTSs). A large fraction of the new PMS objects (5/9) have very low masses as inferred from their late spectral types (≥M5), and comparison with recent evolutionary tracks and Pleiades brown dwarfs suggests that our M6-M6.5 new TTSs are very young brown dwarfs. Two of the new TTSs may constitute a new, moderately embedded, binary classical T Tauri system. The new young stars represent a ∼38% increase in the known PMS population of our survey area and a factor of ∼2 increase in the number of known late-type TTSs. In spite of our sensitivity, we detect no young stars with spectral types later than ∼M7. Our results illustrate the importance of spectroscopy in eliminating foreground M stars.