Type II Supernova - Type IIn Supernovae

Type IIn Supernovae

The "n" denotes narrow, which indicates the presence of intermediate or very narrow width H emission lines in the spectra. In the intermediate width case, the ejecta from the explosion may be interacting strongly with gas around the star – the circumstellar medium. There are indications that they originate as stars similar to Luminous blue variables with large mass losses before exploding. SN 2005gl is one example of Type IIn; SN 2006gy, an extremely energetic supernova, may be another example.