  We present positions, kinematics, and the planetary nebula luminosity
function (PNLF) for 35 planetary nebulae (PNe) in the nearest starburst galaxy
IC10 extending out to 3kpc from the galaxy's centre. We take advantage of the
deep imaging and spectroscopic capabilities provided by the spectrograph FOCAS
on the 8.2m Subaru telescope. The PN velocities were measured through the
slitless-spectroscopy technique, which allows us to explore the kinematics of
IC10 with high precision. Using these velocities, we conclude that there is a
kinematic connection between the HI envelope located around IC10 and the
galaxy's PN population. By assuming that the PNe in the central regions and in
the outskirts have similar ages, our results put strong observational
constraints on the past tidal interactions in the Local Group. This is so
because by dating the PN central stars, we, therefore, infer the epoch of a
major episode of star formation likely linked to the first encounter of the HI
extended envelope with the galaxy. Our deep [OIII] images also allow us to use
the PNLF to estimate a distance modulus of 24.1+/-0.25, which is in agreement
with recent results in the literature based on other techniques.
