  We present the results of an intensive coordinated monitoring campaign in the
optical and X-ray wavelength ranges of the low-mass, pre-main sequence star
V410Tau carried out with the aim to study the relation between various
indicators for magnetic activity that probe emission from different atmospheric
layers: optical photometric star spot (rotation) cycle, chromospheric Halpha
emission, and coronal X-rays. Two X-ray pointings were carried out with the
Chandra satellite simultaneously with the optical observations, and centered
near the maximum and minimum levels of the optical lightcurve. A relation of
their different count levels to the rotation period of the dominating spot is
not confirmed by a third Chandra observation carried out some months later,
during another minimum of the 1.87d cycle. Similarly we find no indications for
a correlation of the Halpha emission with the spots' rotational phase. The
extraordinary stability of the largest spot is confirmed by long-term
photometric and radial velocity measurements. Joining our optical photometry
with previous data we provide a new estimate for the dominant periodicity of
V410Tau. This updated value removes systematic offsets of the time of minimum
observed in data taken over the last decade. Furthermore, the combination of
the new data with published measurements taken during the last decade allows us
to examine long-term changes in the mean light level of the photometry of
V410Tau. A variation on the timescale of 5.4yr is suggested. Assuming that this
behavior is truely cyclic V410Tau is the first pre-main sequence star on which
an activity cycle is detected.
