What is the reason a Type I supernova slows its dimming after about 2 months?
A)The planetary nebula cooled enough to form a dust shell.
B)Energy is released from the decay of radioactive cobalt 56 to iron 56.
C)The supernova remnant suddenly becomes transparent.
D)The burst of energy carried by neutrinos is finally observed.
E)Energy from the supernova's shock wave is released as it hits interstellar matter.

Question

Quizplus · Accepted Answer

After about 2 months, a Type I supernova slows its dimming because energy is released from the decay of radioactive cobalt 56 to iron 56. This process is known as radioactive decay, and it releases a significant amount of energy that can sustain the brightness of the supernova for a longer period of time. After the initial burst of energy from the supernova explosion, the decay of radioactive cobalt 56 to iron 56 releases additional energy that keeps the supernova bright for about 2 months. After this time, the radioactive decay rate slows down and the supernova begins to dim, but at a slower rate than before due to the release of this additional energy.

What Is the Reason a Type I Supernova Slows Its