Context. Most howardite-eucrite-diogenite (HED) meteorites (analogues to
V-type asteroids) are thought to originate from the asteroid (4) Vesta.
However some HEDs show distinct oxygen isotope ratios and therefore are
thought to originate from other asteroids. In this study we try to
identify asteroids that may represent parent bodies of those mismatching
HEDs. Aims: The main goal of this study is to test the hypothesis
that there might be V-type asteroids in the inner main asteroid belt
unrelated to (4) Vesta. In order to evolve outside the Vesta family and
became Vesta fugitives, asteroids should produce the correct Yarkovsky
drift. The direction of which is dependent on asteroid sense of
rotation. Therefore we focus on determining sense of rotation for
asteroids outside the Vesta family to better understand their origin.
Methods: We performed photometric observations using the 1.1 m
and 1.8 m telescopes at Lowell Observatory to determine rotational
synodic periods of selected objects before, at, and after opposition.
Prograde rotators show a minimum in synodic period at opposition while
retrograde rotators show a maximum. This is known as the "drifting
minima" method. Changes in the rotational period are on the order of
seconds and fractions of seconds and depend on the rotational pole of
the object and the asteroid-observer-Sun geometry at opposition.
Results: We have determined sense of rotation for eight asteroids and
retrieved spin states for three objects from literature. For one
asteroid we were not able to determine the sense of rotation. In total
our sample includes 11 V-type asteroids and one S-type (test object). We
have revised rotation periods for three objects. Five V-types in our
sample can be explained by migration from the Vesta family. Two show
spin states that are inconsistent with migration from Vesta. The origin
of the remaining objects is ambiguous. Conclusions: We found two
objects with rotations inconsistent with migration from Vesta. Assuming
that the YORP effect and random collisions did not substantially modify
their sense of rotation, those objects are candidates for non-Vestoids
in the inner asteroid belt. Finding more non-Vestoids is crucial in
testing the formation and migration theory of differentiated parent