We report updated results for the first 7 years of our program to monitor 27 galaxies within 10 Mpc using the Large Binocular Telescope to search for failed supernovae ( SNe ) — core-collapses of massive stars that form black holes without luminous supernovae .
In the new data , we identify no new compelling candidates and confirm the existing candidate .
Given the 6 successful core-collapse SNe in the sample and one likely failed SN , the implied fraction of core-collapses that result in failed SNe is f = 0.14 ^ { +0.33 } _ { -0.10 } at 90 \% confidence .
If the current candidate is a failed SN , the fraction of failed SN naturally explains the missing high-mass red supergiant SN progenitors and the black hole mass function .
If the current candidate is ultimately rejected , the data implies a 90 \% confidence upper limit on the failed SN fraction of f < 0.35 .