  We report on a deep X-ray survey of the young (~ 140 Myr), rich open cluster
NGC 2516 obtained with the EPIC camera on board the XMM-Newton satellite. By
combining data from six observations, a high sensitivity, greater than a factor
5 with respect to recent Chandra observations, has been achieved. We detected
431 X-ray sources and 234 of them have as optical counterparts cluster stars
spanning the entire NGC 2516 Main Sequence. The X-ray luminosities of cluster
stars span the range log Lx (erg/s) = 28.4 - 30.8. The representative
temperatures span the 0.3 - 0.6 keV (3.5 - 8 MK) range for the cool component
and 1.0 - 2.0 keV (12 -- 23 MK) for the hot one; similar values are found in
other young open clusters like the Pleiades, IC 2391, and Blanco 1. While no
significant differences are found in X-ray spectra, NGC 2516 solar type stars
are definitely less luminous in X-rays than the nearly coeval Pleiades. The
comparison with a previous ROSAT survey evidence the lack of variability
amplitudes larger than a factor 2 in solar type stars in a ~11 yr time scale of
the cluster and thus activity cycles like in the Sun are probably absent or
different by period and amplitude in young stars.
