Question
Suppose a star 1000 times brighter than our Sun (that is, emitting 1000 times the power) suddenly goes supernova. Using data from Table 7.3: (a) By what factor does its power output increase? (b) How many times brighter than our entire Milky Way galaxy is the supernova? (c) Based on your answers, discuss whether it should be possible to observe supernovas in distant galaxies. Note that there are on the order of $10^{11}$ observable galaxies, the average brightness of which is somewhat less than our own galaxy.

a) $1 \times 10^8$

b) 5

c) Yes, it should be possible to observe super novae since they are brighter than the 10^{11} observable galaxies, each of which contain millions of stars. If a galaxy suddenly brightens by a factor of ~5, this indicates a super nova occurred.

Solution Video