Cosmology, Page 89

Cosmology, Page 89: [Previous Page] [Next Page] [Class Home Page] Textbook pages 439 - 450

Using Supernovae to get Distances

Type I supernova come about due to the complete destruction of a white dwarf star, as it is pushed over the upper mass limit (Chandrasekhar Limit) of 1.4 Msuns.

While the peak luminosity of Type Ia supernova are not identical, by correcting for the different fall off periods, found to be correlated with peak luminosity, one can determine absolute luminosity quite accurately. Exhaustive searches for Type Ia supernova have been going on for several years now. This is an example of a supernova discovered in a galaxy a billion light years away.

Note the name of the supernova: 1998ba. 1998a is the first SN discovered in 1998. 1998aa would be the 25th. 1998ba was the 49th supernova discovered in 1998, and many more were discovered before the end of the year. In the last few years, typically hundreds of supernova are discovered each year due to concentrated efforts to determine distances to galaxies.