  We present the results of a pathfinder project conducted with the Giant
Metrewave Radio Telescope (GMRT) to investigate protostellar systems at low
radio frequencies. The goal of these investigations is to locate the break in
the free-free spectrum where the optical depth equals unity in order to
constrain physical parameters of these systems, such as the mass of the ionised
gas surrounding these young stars. We detect all three target sources, L1551
IRS 5 (Class I), T Tau and DG Tau (Class II), at frequencies 323 and 608 MHz
(wavelengths 90 and 50 cm, respectively). These are the first detections of low
mass young stellar objects (YSOs) at such low frequencies. We combine these new
GMRT data with archival information to construct the spectral energy
distributions for each system and find a continuation of the optically thin
free-free spectra extrapolated from higher radio frequencies to 323 MHz for
each target. We use these results to place limits on the masses of the ionised
gas and average electron densities associated with these young systems on
scales of ~1000 au. Future observations with higher angular resolution at lower
frequencies are required to constrain these physical parameters further.
