The nearby SN 2017eaw is a Type II-P (“plateau”) supernova (SN) showing early-time,
moderate CSM interaction. We present a comprehensive study of this SN, including the
analysis of high-quality optical photometry and spectroscopy covering the very early
epochs up to the nebular phase, as well as near-ultraviolet and near-infrared spectra
and early-time X-ray and radio data. The combined data of SNe 2017eaw and 2004et allow
us to get an improved distance to the host galaxy, NGC 6946, of D ∼ 6.85 ± 0.63 Mpc;
this fits into recent independent results on the distance of the host and disfavors
the previously derived (30% shorter) distances based on SN 2004et. From modeling the
nebular spectra and the quasi-bolometric light curve, we estimate the progenitor mass
and some basic physical parameters for the explosion and ejecta. Our results agree
well with previous reports on a red supergiant progenitor star with a mass of ∼15–16
M ⊙. Our estimation of the pre-explosion mass-loss rate (\\dot{M}∼ 3× {10}-7{--}1×
{10}-6{M}ȯ yr‑1) agrees well with previous results based on the opacity of the dust
shell enshrouding the progenitor, but it is orders of magnitude lower than previous
estimates based on general light-curve modeling of Type II-P SNe. Combining late-time
optical and mid-infrared data, a clear excess at 4.5 μm can be seen, supporting the
previous statements on the (moderate) dust formation in the vicinity of SN 2017eaw.
