Question

The initial mass of some stars is given below as options. Which of the following stars would become a red giant?

• A. $34\times {10}^{30}\text{kg}$
• B. $18\times {10}^{30}\text{kg}$
• C. $8\times {10}^{30}\text{kg}$
• D. $26\times {10}^{30}\text{kg}$

Answer 1

The correct option is C $8\times {10}^{30}\text{kg}$

A star can become a red giant in the last parts of its life if its initial mass is less than 8 times the Sun's mass.

We know that the mass of the Sun, ${\text{M}}_{\text{Sun}}=2\times {10}^{30}\text{kg}$

Now, find the star that has a mass less than 8 times the mass of the Sun.

$8\times {10}^{30}\text{kg}=\frac{8\times {10}^{30}\text{kg}}{2\times {10}^{30}\text{kg}}=4{\text{M}}_{\text{Sun}}$


Therefore, $8\times {10}^{30}\text{kg}$ mass star would become a red giant.