Progenitor
There are two alternatives, a high-mass 25-40 solar masses star or smaller star with mass of 8-10 solar masses. As there is no evidence that neutron star was formed during the collapse of the star, it is likely that star was in upper spectrum of the mass.Remnants
Observations of the light curve from SN 1997D showed no evidence of other energy sources in the expanding supernova envelope therefore it is unlikely that a Neutron star was created, all the evidence leads to the creation of theReferences
From twilight to highlight: the physics of supernovae : proceedings of the ... By Wolfgang Hillebrandt, Bruno Leibundgut The fading of supernova 1997D Benetti, S., Turatto, M., Balberg, S., Zampieri, L., Shapiro, S. L., Cappellaro {{DEFAULTSORT:SN 1997D Supernovae Reticulum (constellation)