What are the different types of Supernova Remnants?
There are three generally accepted types of SNRs. Note that the categories are not set in stone – SNRs have been observed in the process of gradually transforming from one type to another (Sakhibov & Smirnov 1982; Lazendic et al. 2000). The three types are: • Shell-type remnants: As the shock wave from the supernova explosion ploughs through space, it heats and stirs up any interstellar material it encounters, thus producing a big shell of hot material in space. A ring like structure in this type of remnant is seen because at the edge of the shell there is more hot gas in our line of sight than in the middle. Astronomers call this phenomenon limb brightening. The vast majority of SNRs are of this type. • Crab-like remnants: These remnants, also known as “plerions” (a term first suggested by Weiler & Panagia (1978), and from the Greek word meaning “full”) are similar to the Crab Nebula. They are similar to shell-type remnants, except that they contain a pulsar in the middle that blows o
