Precursors prior to Type IIn supernova explosions are common: precursor rates, properties, and correlations

Understand

There is a growing number of supernovae (SNe), mainly of Type IIn, which present an outburst prior to their presumably final explosion.

• These precursors may affect the SN display, and are likely related to some poorly charted phenomena in the final stages of stellar evolution.
• Here we present a sample of 16 SNe IIn for which we have Palomar Transient Factory (PTF) observations obtained prior to the SN explosion.
• By coadding these images taken prior to the explosion in time bins, we search for precursor events.