Two stars in a faraway part of the Milky Way are orbiting each other as a binary star system. By
careful measurement we find out that they are separated by 1.7 AU. We also determine that
their orbital period is 594 Earth-days. The total mass of the two-object system is

Respuesta :

Answer: [tex]M_{total}=[/tex] 1.85

Explanation: Estimate the total mass of a binary system is done by a reformulation of Kepler's Third Law, which states that the square of the period of a planet's orbit is proportional to the cube of its semimajor axis, i.e.:

[tex]a^{3}=(M_{1}+M_{2})P^{2}[/tex]

where

a is semimajor axis in astronomical units (AU);

P is period measured in years;

[tex]M_{1}+M_{2}[/tex] is total mass of the two-stars system;

For the two stars faraway in the Milky Way:

1 year is equivalent of 365 days, so period in years:

[tex]P=\frac{594}{365}[/tex]

P = 1.63 years

Calculating total mass:

[tex]a^{3}=(M_{total})P^{2}[/tex]

[tex]M_{total}=\frac{a^{3}}{P^{2}}[/tex]

[tex]M_{total}=\frac{1.7^{3}}{1.63^{2}}[/tex]

[tex]M_{total}=[/tex] 1.85

The total mass of the two-object system is 1.85 mass units.