MUSE observations of NGC330 in the Small Magellanic Cloud. Helium
  abundance of bright main sequence stars
  We present observations of the most bright main sequence stars in the Small
Magellanic Cloud stellar cluster NGC330 obtained with the integral field
spectrograph MUSE@VLT. The use of this valuable instrument allows us to study
both photometric and spectroscopic properties of stellar populations of this
young star cluster.
  The photometric data provide us a precise color magnitude diagram, which
seems to support the presence of two stellar populations of ages of $\sim$ 18
Myr and $\sim$ 30 Myr assuming a metallicity of Z = 0.002. Thanks to the
spectroscopic data, we derive helium abundance of 10 main sequence stars within
the effective radius Reff= 20" of NGC330, thus leading to an estimation of
$\epsilon(He)$ = 10.93 $\pm$ 0.05 (1$\sigma$ ). The helium elemental abundances
of stars likely belonging to the two possible stellar populations, do not show
differences or dichotomy within the uncertainties. Thus, our results suggest
that the two stellar populations of NGC330, if they exist, share similar
original He abundances.
  If we consider stellar rotation velocity in our analysis, a coeval (30 Myr)
stellar population, experiencing different values of rotation, cannot be
excluded. In this case, the mean helium abundance < $\epsilon(He)$ >rot
obtained in our analysis is 11.00 $\pm$ 0.05 dex. We also verified that
possible NLTE effects cannot be identified with our analysis because of the
spectral resolution and they are within our derived abundance He uncertainties.
  Moreover, the analysis of the He abundance as a function of the distance from
the cluster center of the observed stars do not show any correlation.
