Type II intermediate-luminosity optical transients (ILOTs)
  We propose that in a small fraction of intermediate luminosity optical
transients (ILOTs) powered by a strongly interacting binary system, the ejected
mass in the equatorial plane can block the central source from our line of
sight. We can therefore observe only radiation that is reprocessed by polar
outflow, much as in type~II active galactic nuclei (AGN). An ejection of
$M_{\rm ej,e}=10^{-4} ~\rm{M_\odot} ~ (1 ~\rm{M_\odot})$ at 30 degrees from the
equatorial plane and at a velocity of $v_{\rm e} = 100 ~\rm{km~s^{-1}}$ will
block the central source in the NIR for about 5 years (500 years). During that
period of time the object might disappear in the visible band, and be detected
only in the IR band due to polar dust. We raise the possibility that the
recently observed disappearance of a red giant in the visible, designated
N6946-BH1, is a type~II ILOT rather than a failed supernova. For this case we
estimate that the ejected mass in the polar direction was $M_{\rm ej,p}\approx
10^{-3} ~\rm{M_\odot}$. Our scenario predicts that this event should reinstate
its visible emission in several decades.
