  Asteroids of size larger than 150 m generally do not have rotation periods
smaller than 2.2 hours. This spin cutoff is believed to be due to the
gravitationally bound rubble-pile structures of the asteroids. Rotation with
periods exceeding this critical value will cause asteroid breakup. Up until
now, only one object, 2001 OE84, has been found to be an exception to this spin
cutoff. We report the discovery of a new super-fast rotator, (335433) 2005
UW163, spinning with a period of 1.290 hours and a lightcurve variation of
$r'\sim0.8$ mag from the observations made at the P48 telescope and the P200
telescope of the Palomar Observatory. Its $H_{r'} = 17.69 \pm 0.27$ mag and
multi-band colors (i.e., $g'-r' = 0.68\pm0.03$ mag, $r'-i' = 0.19\pm0.02$ mag
and SDSS $i-z = -0.45$ mag) show it is a V-type asteroid with a diameter of
$0.6 +0.3/-0.2$ km. This indicates (335433) 2005 UW163 is a super-fast rotator
beyond the regime of the small monolithic asteroid.
