  In a framework where galaxies mostly migrate on the colour-magnitude diagram
from star-forming to quiescent, the green valley is considered a transitional
galaxy stage. The details of the processes that drive galaxies from
star-forming to passive systems still remain unknown. We developed a method
that estimates empirically the star formation quenching times-scales of green
valley galaxies, assuming an exponential decay model of the SFH and through a
combination of narrow and broad bands from J-PLUS and GALEX. We correlate these
quenching time-scales with the presence of bars. We find that the J-PLUS
colours F0395-g and F0415-g are sensitive to different SFH, showing, a clear
correlation with the Dn(4000) and H-delta,A spectral indices. We find that
quenching time-scales obtained with our new approach are in agreement with
those determined using spectral indices. We also find that galaxies with high
bar probability tend to quench their star formation slowly. We conclude that:
1) J-PLUS filters can be used to measure quenching timescales in nearby green
valley galaxies; and 2) the resulting star formation quenching time-scales are
longer for barred green valley galaxies. Considering that the presence of a bar
indicates that more violent processes (e.g., major mergers) are absent in host
galaxies, we conclude that the presence of a bar can be used as a morphological
signature for slow star formation quenching.
