  The periods of rotation and activity cycles are among the most important
properties of the magnetic dynamo thought to be operating in late-type,
main-sequence stars. In this paper, we present a S$_{\rm{MWO}}$-index time
series composed from different data sources for the solar-like star HD 140538
and derive a period of 3.88$\pm$0.02 yr for its activity cycle. Furthermore, we
analyse the high-cadence, seasonal S$_{\rm{MWO}}$ data taken with the TIGRE
telescope and find a rotational period of 20.71$\pm$0.32 days. In addition, we
estimate the stellar age of HD 140538 as 3.7 Gyrs via a matching evolutionary
track. This is slightly older than the ages obtained from gyrochronology based
on the above rotation period, as well as the activity-age relation. These
results, together with its stellar parameters that are very similar to a
younger Sun, make HD 140538 a relevant case study for our understanding of
solar activity and its evolution with time.
