  In the framework of the Visible NEAs Observations Survey (ViNOS) that uses
several telescopes at the Canary Islands observatories since 2018, we observed
two super fast rotator NEAs, 2021 NY$_1$ and 2022 AB. We obtained photometry
and spectrophotometry of both targets and visible spectroscopy of 2022 AB.
Light curves of 2021 NY$_1$ obtained in 4 different nights between Sept. 30 and
Oct. 16, 2021 return a rotation period $P=13.3449\pm0.0013$ minutes and a light
curve amplitude $A = 1.00$ mag. We found that 2021 NY$_1$ is a very elongated
super fast rotator with an axis ratio $a/b \ge 3.6$. We also report colours
$(g-r) = 0.664 \pm 0.013$, $(r-i) = 0.186 \pm 0.013$, and $(i-z_s) = -0.117 \pm
0.012$ mag. These are compatible with an S-type asteroid. The light curves of
2022 AB obtained on Jan. 5 and Jan. 8, 2021 show a rotation period
$P=3.0304\pm0.0008$ minutes, with amplitudes $A = 0.52$ and $A =0.54$ mag. 2022
AB is also an elongated object with axis ratio $a/b \ge 1.6$. The obtained
colours are $(g-r) = 0.400 \pm 0.017$, $(r-i) = 0.133 \pm 0.017$, and $(i-z_s)
= 0.093 \pm 0.016$. These colours are similar to those of the X-types, but with
an unusually high $(g-r)$ value. Spectra obtained on Jan. 12 and Jan. 14, 2022,
are consistent with the reported colours. The spectral upturn over the 0.4 -
0.6 $\mu m $ region of 2022 AB does not fit with any known asteroid taxonomical
class or meteorite spectrum, confirming its unusual surface properties.
