Four brown dwarfs in the Taurus star-forming region

We have identified four brown dwarfs in the Taurus star-forming region. The y were first selected from R and I CCD photometry of 2.29 deg(2) obtained a t the Canada-France-Hawaii Telescope. Subsequently, they were recovered in the Two Micron All Sky Survey second incremental data release point source catalog. Low-resolution optical spectra obtained at the William Herschel Te lescope allow us to derive spectral types in the range M7-M9. One of the br own dwarfs has very strong H alpha emission (EW = -340 Angstrom). It also d isplays Br gamma emission in an infrared spectrum obtained with the Infrare d Camera and Spectrograph on the Subaru telescope, suggesting that it is ac creting matter from a disk. The K I resonance doublet and the Na I subordin ate doublet at 818.3 and 819.5 nm in these Taurus objects are weaker than i n field dwarfs of similar spectral type, consistent with low surface gravit ies as expected for young brown dwarfs. Two of the objects are cooler and f ainter than GG Tau Bb, the lowest mass known member of the Taurus associati on. We estimate masses of only 0.03 M-circle dot for them. The spatial dist ribution of brown dwarfs in Taurus hints at a possible anticorrelation betw een the density of stars and the density of brown dwarfs.