  From a set of adaptive optics (AO) observations collected with the W.M. Keck
telescope between August and September 2009, we derived the orbital parameters
of the most recently discovered satellites of the large C-type asteroid (93)
Minerva. The satellites of Minerva, which are approximately 3 and 4 km in
diameter, orbit very close to the primary $\sim$5 & $\sim$8 $\times$ Rp and
$\sim$1% & $\sim$2% $\times$ RHill) in a circular manner, sharing common
characteristics with most of the triple asteroid systems in the main-belt.
Combining these AO observations with lightcurve data collected since 1980 and
two stellar occultations in 2010 & 2011, we removed the ambiguity of the pole
solution of Minerva's primary and showed that it has an almost regular shape
with an equivalent diameter Deq = 154 $\pm$ 6 km in agreement with IRAS
observations. The surprisingly high bulk density of 1.75 $\pm$ 0.30 g/cm$\^3$
for this C-type asteroid, suggests that this taxonomic class is composed of
asteroids with different compositions, For instance, Minerva could be made of
the same material as dry CR, CO, and CV meteorites. We discuss possible
scenarios on the origin of the system and conclude that future observations may
shine light on the nature and composition of this fifth known triple main-belt
asteroid.
