Near-infrared colour-colour diagram of sources around HR 8119. Grey asterisks are 2MASS sources with good photometry located at a maximum angular distance of 30′ from HR 8119 (see red circle in Fig. 2). Contours indicate the source density. The continuous and dashed lines are the loci of main-sequence and giant stars of Bessell & Brett (1988). The dotted-dashed line is the locus of the classical T Tauri stars (Meyer et al. 1997). The arrows show the extinction vectors (Cohen et al. 1981). The classical T Tauri star candidates are labelled.