To determine which of these stars will stay on the main sequence for the longest time, we need to consider the general relationship between a star's mass and its lifespan on the main sequence. Generally, stars with smaller masses have longer lifespans on the main sequence because they burn their nuclear fuel more slowly compared to more massive stars.
Let's examine the initial masses given for each star:
- Star 1 has an initial mass of 9 solar masses.
- Star 2 has an initial mass of 0.9 solar masses.
- Star 3 has an initial mass of 5 solar masses.
- Star 4 has an initial mass of 0.3 solar masses.
Since stars with smaller masses have longer lifespans, we need to identify the star with the smallest initial mass. Here, we can list the masses in ascending order to easily find the smallest one:
- Star 4: 0.3 solar masses
- Star 2: 0.9 solar masses
- Star 3: 5 solar masses
- Star 1: 9 solar masses
Clearly, Star 4 has the smallest initial mass of 0.3 solar masses. Hence, Star 4 will stay on the main sequence for the longest time.
So, the star that will stay on the main sequence for the longest time is:
Star 4
