  We study the photospheric evolution of an exploding granule observed in the
quiet Sun at high spatial ($0.3^{\prime\prime}$) and temporal (31.5 s)
resolution by the imaging magnetograph Sunrise/IMaX in June 2009. These
observations show that the exploding granule is cospatial to a magnetic flux
emergence event occurring at mesogranular scale (up to 12 Mm$^{2}$ area). Using
a modified version of the SIR code for inverting the IMaX spectropolarimetric
measurements, we obtain information about the magnetic configuration of this
photospheric feature. In particular, we find evidence of highly inclined
emerging fields in the structure, carrying a magnetic flux content up to $4
\times 10^{18}$ Mx. The balance between gas and magnetic pressure in the region
of flux emergence, compared with a very quiet region of the Sun, indicates that
the additional pressure carried by the emerging flux increases by about 5% the
total pressure and appears to allow the granulation to be modified, as
predicted by numerical simulations. The overall characteristics suggest that a
multi-polar structure emerges into the photosphere, resembling an almost
horizontal flux sheet. This seems to be associated with exploding granules.
Finally, we discuss the origin of such flux emergence events.
