  The X-ray source RX J004717.4-251811 in the nearby starburst galaxy NGC 253
was found to undergo changes from a low to a high state twice, during an
XMM-Newton EPIC observation in December 2000 and also during a Chandra
observation one year earlier. These transitions are interpreted as egresses
from eclipses of a compact object in a high mass X-ray binary system (HMXB).
The phase of eclipse egress during the Chandra observation is given by
barycenter corrected MJD 51539.276+-0.006 and the binary period determined to p
= (352.870+-0.012) d / n by the time difference between the two egresses and
number n of periods in-between. Allowed periods may be further constrained by
additional XMM-Newton, Chandra, ROSAT, and Einstein observations resulting in
only seven acceptable periods with 1.47024 d and 3.20793 d most promising. No
significant regular pulsations of the source in the range 0.3-1000 s were
found. Fluctuations on time scales of 1000 s were observed together with
extended intervals of low intensity. The energy spectrum during the bright
state can best be described by an absorbed flat power law (NH=1.9x10^21 cm^-2,
Gamma=1.7). In the bright state the source luminosity is 4x10^38 erg/s (0.5--5
keV), just compatible with the Eddington luminosity of a 1.4 M_sun neutron
star. A possible optical identification is suggested. RX J004717.4-251811
parameters are compared to other eclipsing X-ray binaries (XRBs).
