Author Question: During the T-Tauri phase of a protostar, it A) begins a period of reduced activity. B) expands ... (Read 19 times)

skymedlock · **on:** Jul 27, 2018

During the T-Tauri phase of a protostar, it

A) begins a period of reduced activity.
B) expands dramatically.
C) may develop very strong winds.
D) lies on the main sequence.
E) changes its spin direction.

Question 2

Why were Type I supernovae so critical in discovering dark energy?

What will be an ideal response?

ynlevi · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

C

Answer to Question 2

These brilliant explosions are consistent standard candles, visible out to billions of light-years. Instead of finding the most distant galaxies slowing down as expected in a closed universe, the supernovae were even more distant than expected, as dark energy kept the universe forever expanding.