  We present the results obtained by analysing new Astrosat/UVIT far
ultraviolet (FUV) image of the collisional-ring galaxy Cartwheel. The FUV
emission is principally associated with the star-forming outer ring, with no UV
detection from the nucleus and inner ring. A few sources are detected in the
region between the inner and the outer rings, all of which lie along the
spokes. The FUV fluxes from the detected sources are combined with
aperture-matched multi-band photometric data from archival images to explore
the post-collision star formation history of the Cartwheel. The data were
corrected for extinction using Av derived from the Balmer decrement ratios and
commonly used extinction curves. We find that the ring regions contain stellar
populations of wide range of ages, with the bulk of the FUV emission coming
from non-ionizing stars, formed over the last 20 to 150 Myr, that are ~25 times
more massive than the ionizing populations. On the other hand, regions
belonging to the spokes have negligible current star formation, with the age of
the dominant older population systematically increasing as its distance from
the outer ring increases. The presence of populations of a wide range of ages
in the ring suggests that the stars formed in the wave in the past were dragged
along it to the current position of the ring. We derive an average steady star
formation rate, SFR=5 Msun/yr, over the past 150 Myr, with an increase to ~18
Msun/yr in the recent 10 Myr.
