  Chandra data of the X-ray source [PMH2004] 47 were obtained in the ACIS
Survey of M 33 (ChASeM33) in 2006. During one of the observations, the source
varied from a high state to a low state and back, in two other observations it
varied from a low state to respectively intermediate states. These transitions
are interpreted as eclipse ingress and egresses of a compact object in a high
mass X-ray binary system. The phase of mid eclipse is given by HJD
2453997.476+-0.006, the eclipse half angle is 30.6+-1.2 degree. Adding
XMM-Newton observations of [PMH2004] 47 in 2001 we determine the binary period
to be 1.732479+-0.000027 d. This period is also consistent with ROSAT HRI
observations of the source in 1994. No short term periodicity compatible with a
rotation period of the compact object is detected. There are indications for a
long term variability similar to that detected for Her X-1. During the high
state the spectrum of the source is hard (power law spectrum with photon index
~0.85) with an unabsorbed luminosity of 2E37 erg/cm2/s (0.2-4.5 keV). We
identify as an optical counterpart a V ~ 21.0mag star with T_eff > 19000 K,
log(g) > 2.5. CFHT optical light curves for this star show an ellipsoidal
variation with the same period as the X-ray light curve. The optical light
curve together with the X-ray eclipse can be modeled by a compact object with a
mass consistent with a neutron star or a black hole in a high mass X-ray
binary. However, the hard power law X-ray spectrum favors a neutron star as the
compact object in this second eclipsing X-ray binary in M 33. Assuming a
neutron star with a canonical mass of 1.4 M_sun and the best fit companion
temperature of 33000 K, a system inclination i = 72 degree and a companion mass
of 10.9 M_sun are implied.
