Friday

Type IIn supernovae (SNeIIn) are proposed to be a class of core-collapse supernovae (CCSNe) which occur within a dense circumstellar medium (CSM) that leads to the signature narrow component on H lines. SNeIIn are a fairly uncommon and mysterious SN type accounting for around 7% of all classified SNe. The mysteriousness of SNeIIn regards the progenitor path. CCSNe are the terminal explosions of high mass stars and the progenitors of SNeIIn are often attributed to Luminous Blue Variables (LBVs). Therefore, one would expect SNeIIn to be associated with regions of star formation. But Habergham et al. (2014) have suggested this may not be not the case. Those authors found that SNeIIn poorly trace H-alpha emission with a potential bimodal population in the association of star formation as traced by H-alpha with some sites being strongly associated and other being far away from areas of star formation. We present the findings from the largest H-alpha survey of the environments of SNeIIn yet undertaken. We investigate the possibility of bimodal levels of association with star formation which may suggest multiple progenitor paths. Potential lower mass progenitors being electron-capture supernovae, mergers that produce an LBV and SNeIa that explode in a dense circumstelar medium. Further to this some SNeIIn (notably SN2005ip) have long-lasting H-alpha emission long after the eruption. We will investigate whether any objects in our sample/the proportion of our sample exhibit this behaviour. We also present a spectral classification scheme for SNeIIn which is applied to our sample where we find ~40% of SNeIIn are misclassified in public databases.