  WR~102-1 was detected by Suzaku as a conspicuous point source in the 6.7 keV
intensity map of the central region of the Milky Way. The source was suggested
as a possible Wolf-Rayet binary based on its X-ray and infrared spectral
characteristics. The iron line emission is expected to originate in the
Wolf-Rayet star's dynamic stellar-wind when colliding the companion's mild
stellar wind. Here, we report the result of a long-term X-ray monitoring of
WR~102-1 since 1998 using archival data of ASCA, XMM-Newton, Chandra, Suzaku,
and Swift to reveal variations of the iron K-emission line and the
circumstellar absorption. Consequently, we have detected significant redshifts
of the iron K-emission line from the XMM-Newton observation in March 2003 and
the Suzaku observation in September 2006. Furthermore, when the red-shift was
observed, which suggests that the Wolf-Rayet star was in front of the companion
star, the circumstellar absorption values were smaller than other periods.
These results appear contrary to the expectation if the Wolf-Rayet's stellar
wind is spherically symmetric, but may be understood if the Wolf-Rayet star's
stellar wind is significantly distorted due to the rapid orbital motion near
the periastron.
