What is the difference between a Type II-P supernova and a Type II-n supernova?

Supernovae are massive explosions that occur at the end of a star's life, and they play a crucial role in the evolution of the universe. There are different types of supernovae, and they are classified based on the presence or absence of certain spectral lines in their spectra.

Type II supernovae are characterized by the presence of hydrogen lines in their spectra, and they are further classified into subtypes based on the evolution of their light curve. Type II-P supernovae have a plateau phase in their light curve, where the luminosity remains constant for a period of time before declining. Type II-n supernovae, on the other hand, have a narrow peak in their light curve and then decline rapidly.

The difference in the light curve of Type II-P and Type II-n supernovae is due to the difference in their progenitor stars. Type II-P supernovae are believed to be the explosions of red supergiants, while Type II-n supernovae are thought to be the explosions of blue supergiants. The mass of the progenitor star also plays a role in determining the subtype of the supernova. Type II-P supernovae are thought to be the result of stars with initial masses between 8 and 25 times that of the sun, while Type II-n supernovae are thought to be the result of stars with initial masses greater than 25 times that of the sun.

In summary, Type II-P supernovae and Type II-n supernovae are both Type II supernovae, but they differ in their light curves and progenitor stars. Type II-P supernovae have a plateau phase in their light curve and are believed to be the explosions of red supergiants with initial masses between 8 and 25 times that of the sun. Type II-n supernovae, on the other hand, have a narrow peak in their light curve and are thought to be the explosions of blue supergiants with initial masses greater than 25 times that of the sun.