Type II-P Supernovae Usually Remain Bright for About 100 Days. But iPTF14hls Remained Bright for Mor (image) Carnegie Institution for Science Share Print E-Mail Caption iPTF14hls grew bright and dim again at least five times over two years. This behavior has never been seen in previous supernovae, which typically remain bright for approximately 100 days and then fade. Credit Adapted from Arcavi et al. 2017, Nature. Credit: LCO/S. Wilkinson. Usage Restrictions With credit Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.