  The aim of this work is to identify the so far unknown low mass stellar
population of the ~2Myr old Cygnus OB2 region, and to investigate the X-ray and
near-IR stellar properties of its members. We analyzed a 97.7 ksec Chandra
ACIS-I observation pointed at the core of the Cygnus OB2 region. X-ray
variability ans spectral analysis of sources was characterized through the
KS-test and XSPEC thermal models, respectively. We detected 1003 X-ray sources.
Of these, 775 have near-IR counterparts associated with Cygnus OB2 members. We
estimate a typical absorption toward Cygnus OB2 of Av~7.0 mag. Although the
region is young, very few stars (~4.4 %) show disk-induced excesses in the
near-IR. X-ray variability is detected in ~13 % of the sources. Flares account
for at least 60 % of the variability. O- that early B-type stars are not
significantly variable. Typical X-ray spectral parameters are log(Nh)~22.25 and
kT~1.35 keV. Variable and flaring sources have harder spectra with median
kT=3.3 and 3.8 keV, respectively. OB stars are typically softer (kT~0.75 keV).
X-ray luminosities range between 1E+30 and 1E+31 erg/s for intermediate- and
low-mass stars, and 2.5x10^30 and between 6.3E+33 erg/s for OB stars. The
Cygnus OB2 region has a very rich population of low-mass X-ray emitting stars.
Circumstellar disks seem to be very scarce.
