The distance, supernova rate and supernova progenitors of NGC 6946
  The distance to the fireworks galaxy NGC 6946 is highly uncertain. Recent
distance estimates using the tip of the red giant branch of 7.7 to 7.8 Mpc are
larger than the distance commonly assumed for studying supernovae in this
galaxy of 5.9 Mpc. Here we use the high supernova rate of the galaxy to derive
the star-formation rate and predict the galaxy's FUV flux. We also account for
dust extinction by different methods to derive a distance of 7.9+/-4.0 Mpc for
NGC 6946. We then use the new distance to re-evaluate the understanding of the
supernova progenitors 2002hh, 2004et, 2017eaw, the possible electron capture
event 2008S and the possible black-hole forming event N6946-BH1. For the latter
two exotic events the new distance improves the consistency between the
observed progenitors and the stellar models that give rise to these events.
From our findings we strongly recommend that all future studies of NGC~6946
must use the greater distance to the galaxy of 7.72+/-0.32 Mpc of Anand et al.
(2018).
