Very low-mass members of the Lupus 3 cloud

Abstract

We report on a multi-band survey for very low-mass stars and brown dwarfs in the Lupus 3 cloud with the Wide Field Imager (WFI) at the ESO/MPG 2.2m telescope on La Silla Observatory (Chile). Our multiband optical photometry is combined with available 2MASS JHK photometry to identify 19 new young stars and 3 brown dwarf candidates as probable members of this star forming region. Our objects are mostly clustered around the cloud core. Stars and brown dwarfs have similar levels of H-alpha emission, probably a signature of accretion. One object, a brown dwarf candidate, exhibits a near-infrared excess, which may indicate the presence of a disk, but its H-alpha emission cannot be confirmed due to its faintness in the optical passbands. We also find two visual pairs of probable Lupus 3 members that may be wide binaries.