The fading of supernova 1997D

We present a new set of spectroscopic and photometric data extending the ob servations of SN 1997D to over 400 d after the explosion. These observation s confirm the peculiar properties of SN 1997D, such as the very low abundan ce of Co-56 (0.002 M.) and the low expansion velocity of the ejecta (simila r to 1000 km s(-1)). We discuss the implications of these observations for the character of the progenitor and the nature of the remnant, showing that a Crab-like pulsar or an accreting neutron star formed in the explosion of a low-mass progenitor should already have produced a detectable luminosity at this epoch, in contrast with photometric data. On the other hand, the e xplosion of a high-mass progenitor with the formation of a black hole is co nsistent with the available observations. The consequences of this conclusi on regarding the nature of the explosion and the prospects of directly iden tifying the black hole are also addressed.