Very low-mass members of the Lupus 3 cloud

Max-Planck-Institut fu¨r Astronomie, K¨onigstuhl 17, D-69117 Heidelberg, Germanye-mail: mundt@mpia-hd.mpg.deReceived ; acceptedAbstract. We report on a multi-band survey for very low-mass stars and brown dwarfs in the Lupus 3 cloud withthe Wide Field Imager (WFI) at the ESO/MPG 2.2 m telescope on La Silla Observatory (Chile). Our multibandoptical photometry is combined with available 2MASS JHK photometry to identify 19 new young stars and 3brown dwarf candidates as probable members of this star forming region. Our objects are mostly clustered aroundthe cloud core. Stars and brown dwarfs have similar levels of Hα emission, probably a signature of accretion. Oneobject, a brown dwarf candidate, exhibits a near-infrared excess, which may indicate the presence of a disk, butits Hα emission cannot be confirmed due to its faintness in the optical passbands. We also find two visual pairsof probable Lupus 3 members that may be wide binaries.Keywords.stars: low-mass, brown dwarfs – stars: pre-main sequence – stars: formation – stars: luminosity function,mass function – stars: circumstellar matter