Answer:
the force will increase by a factor 2.25
Step-by-step explanation:
The gravitational force between the two stars is given by:
![F=G(m_1 m_2)/(r^2)](https://img.qammunity.org/2020/formulas/physics/high-school/5of4xblxa18x8nkhxlbkmu4q85m003wp30.png)
where
G is the gravitational constant
m1, m2 are the masses of the two stars
r is the distance between the stars
If the distance is decreased by one-third, it means that the new distance is 2/3 of the previous distance
![r'=(2)/(3)r](https://img.qammunity.org/2020/formulas/physics/high-school/33xlok8evpqtxe95vwv4rfiptph2i64cyk.png)
So the new force will be
![F'=G(m_1 m_2)/(((2)/(3)r)^2)=(9)/(4) G(m_1 m_2)/(r^2)=2.25 F](https://img.qammunity.org/2020/formulas/physics/high-school/nc13e3b6dk7ks3jsxqz9mw745mb9rmqqs5.png)
So, the force will be 2.25 times the previous value.