SN 1997D, discovered in January 1997 by Duília de Mello in galaxy NGC 1536 in Reticulum constellation is a first clearly identified example of atypical Type II supernova with a very low luminosity and expansion velocity.
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==
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 the stellar mass black hole of approximately 3 solar masses. ==References==