  We have carried out a long term infrared and X-ray investigation of the
colliding wind binary WR 125 (WC7+O9III). The source was monitored using
AstroSat-Soft X-ray Telescope and TIRCAM2 mounted at the back of 3.6 m
Devasthal Optical Telescope. WR 125 appeared brighter in near infra-red K-band
during the years 2017-2021 which is attributed to another episode of dust
formation similar to the one reported during the likely periastron passage at
the beginning of the 1990s. This is further supported by enhanced emission
observed in W1 and W2 bands of WISE from 2018-19. By combining archival X-ray
data sets with our new measurements, long-term variations have been noticed.
The source reaches a lower emission state in June 2020 (close to the recent
infrared maximum) which could be due to enhanced absorption of X-rays produced
in the colliding wind region by the WC stellar wind close to the periastron in
an eccentric orbit. The time interval between the previous and latest X-ray low
states may indicate an orbital period of 28-29 years, in fair agreement with
the recurrence time of episodic dust production. We also discuss published
radio measurements in the context of a common picture based on a long period
binary scenario. These results allow us to draw relevant guidelines for future
multi-wavelength observations of WR 125.
