Answer:
the force will increase by a factor 2.25
Explanation:
The gravitational force between the two stars is given by:
[tex]F=G\frac{m_1 m_2}{r^2}[/tex]
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
[tex]r'=\frac{2}{3}r[/tex]
So the new force will be
[tex]F'=G\frac{m_1 m_2}{(\frac{2}{3}r)^2}=\frac{9}{4} G\frac{m_1 m_2}{r^2}=2.25 F[/tex]
So, the force will be 2.25 times the previous value.