  Context: The comparison of observed counts in a given sky direction with
predictions by Galactic models yields constraints to the spatial distribution
and the stellar birthrate of young stellar populations. In this work we present
the results of the analysis of the stellar content of the XMM-Newton Bright
Serendipitous Survey (XBSS). This unbiased survey includes a total of 58
stellar sources selected in the 0.5 -- 4.5 keV energy band, having a limiting
sensitivity of $10^{-2}$ cnt s$^{-1}$ and covering an area of 28.10 sq. deg.
Aims: Our main goal is to understand the recent star formation history of the
Galaxy in the vicinity of the Sun. Methods: We compare the observations with
the predictions obtained with XCOUNT, a model of the stellar X-ray content of
the Galaxy. The model predicts the number and properties of the stars to be
observed in terms of magnitude, colour, population and
$f_\mathrm{x}/f_\mathrm{v}$ ratio distributions of the coronal sources detected
with a given instrument and sensitivity in a specific sky direction. Results:
As in other shallow surveys, we observe an excess of stars not predicted by our
Galaxy model. Comparing the colours of the identified infrared counterparts
with the model predictions, we observe that this excess is produced by yellow
(G+K) stars. The study of the X-ray spectrum of each source reveals a main
population of stars with coronal temperature stratification typical of
intermediate-age stars. As no assumptions have been made for the selection of
the sample, our results must be representative of the entire Solar
Neighbourhood. Some stars show excess circumstellar absorption indicative of
youth.
