To determine which star will remain on the main sequence for the shortest time, we need to understand the relationship between a star's mass and its main sequence lifetime.
The main sequence lifetime of a star is inversely related to the cube of its mass. This means that a more massive star will have a shorter main sequence lifetime because it burns through its nuclear fuel more quickly.
Given the initial masses of the stars:
- Star 1: 9 Solar masses
- Star 2: 0.9 Solar masses
- Star 3: 5 Solar masses
- Star 4: 0.3 Solar masses
We want to find the star with the largest mass, as that star will have the shortest main sequence lifetime.
Let’s compare the masses:
- Star 1: 9 Solar masses
- Star 2: 0.9 Solar masses
- Star 3: 5 Solar masses
- Star 4: 0.3 Solar masses
Among these values, the largest mass is 9 Solar masses, which belongs to Star 1.
Hence, Star 1 will stay on the main sequence for the shortest time.
So, the correct answer is:
Star 1
