  Radio observations of young stellar objects (YSOs) enable the study of
ionised plasma outflows from young protostars via their free-free radiation.
Previous studies of the low-mass young system T Tau have used radio
observations to model the spectrum and estimate important physical properties
of the associated ionised plasma (local electron density, ionised gas content
and emission measure). However, without an indication of the low-frequency
turnover in the free-free spectrum, these properties remain difficult to
constrain. This paper presents the detection of T Tau at 149 MHz with the Low
Frequency Array (LOFAR) - the first time a YSO has been observed at such low
frequencies. The recovered total flux indicates that the free-free spectrum may
be turning over near 149 MHz. The spectral energy distribution is fitted and
yields improved constraints on local electron density ($(7.2 \pm
2.1)\times10^{3}$ cm$^{-3}$), ionised gas mass ($(1.0 \pm 1.8)\times10^{-6}$
M$_{\odot}$) and emission measure ($(1.67 \pm 0.14)\times10^5$ pc cm$^{-6}$).
