Based on observations obtained at the European Southern Observatory using the Very Large Telescope in Cerro Paranal (program 67.C-0549(A)), the ESO New Technology Telescope in La Silla (program 69.B-0126(A)), and the 1.5 Danish telescope, also in La Silla (program 69.C-0423(B)).

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

Note that Muzerolle et al. (1998b) use in their plots the flux emitted per unit surface, adopting a fiducial radius of 2 $R_\odot$ for classical T Tauri stars. We rather use the flux integrated over the entire surface in Eq. (1), assuming that the correlation found by Muzerolle et al., which spans over three orders of magnitude in mass loss rate for the classical T Tauri stars in their sample, relates mass accretion rate to total CaII line luminosity, and that it applies also at the lower masses (and radii) of the objects discussed here.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.