On the progenitor of the Type Ibc supernova 2012fh

Abstract

Little is observationally known about the progenitors of Type Ibc supernovae (SNe) or the typical activity of SNe progenitors in their final years. Here, we analyze deep Large Binocular Telescope imaging data spanning the 4 years before and after the Type Ic SN 2012fh using difference imaging. We place 1$\sigma$ upper limits on the detection of the progenitor star at $M_R>-4.0$, $M_V>-3.8$, $M_B>-3.1$, and $M_U>-3.8$ mag. These limits are the tightest placed on a Type Ic SNe and they largely rule out single star evolutionary models in favor of a binary channel as the origin of this SN. We also constrain the activity of the progenitor to be small on an absolute scale, with the RMS $UBVR$ optical variability $<2500L_\odot$ and long-term dimming or brightening trends $<1000L_\odot/\text{year}$ in all four bands.