  We observed the black hole candidate Cyg X-1 for 15 ks with the High-Energy
Transmission Grating Spectrometer aboard the CHANDRA X-ray Observatory. The
source was observed during a period of intense flaring activity, so it was
about a factor of 2.5 brighter than usual, with a 0.5-10 keV (1-24 A)
luminosity of 1.6x10^37 erg/s (at a distance of 2.5 kpc). The spectrum of the
source shows prominent absorption edges, some of which have complicated
substructure. We use the most recent results from laboratory measurements and
and calculations to model the observed substructure of the edges. From the
model, we derive a total absorption column of 6.21+/-0.22 10^21 cm^-2.
Furthermore, the results indicate that there are ~ 10 - 25% abundance
variations relative to solar values for neon, oxygen and iron. The X-ray
continuuum is described well by a two-component model that is often adopted for
black hole candidates: a soft multicolor disk component (with kT = 203 eV) and
a hard power law component (with a photon index of ~2). Comparing the fit
results to those of the hard and soft states, we conclude that the source was
in a transitional state. Finally, the spectrum also shows the presence of faint
emission lines which could be attributed to highly ionized species.
