(Phys.org)—An international team of astronomers has detected a new slowly evolving Type Ibn supernova as part of the Optical Gravitational Lensing Experiment (OGLE). The new event, designated OGLE-2014-SN-13, has the longest rise time ever observed in Type Ibn supernovae. The discovery is described in a paper published Mar. 23 on the arXiv pre-print server.