
Complete Question:
How massive is the brown dwarf
Answer:
Mass of the brown dwarf, M₂ = 4.132 * 10²⁷ kg
Explanation:
Let M₁ = Mass of the main-sequence star
M₂ = Mass of the brown dwarf
v₁ = speed of the main-sequence star
v₂ = speed of the brown dwarf
The average separation of the system r₁ = r₂ = 1 AU
Orbital speed of the brown dwarf is 22 times that of the main - sequence star
That is, v₂ = 22 v₁
Since the sun is a main sequence star
Mass of the main - sequence star = 2 * 10³⁰ kg
Centripetal force, F = Mv²/r
M₁v₁²/r₁² = M₂v₂²/r²
M₁v₁² = M₂v₂²
M₂/M₁ = v₁²/v₂²
M₂/M₁ = (1/22)²
M₂/M₁ = 0.002066
M₂ = 0.002066M₁
M₂ = 0.002066 * 2 * 10³⁰
M₂ = 4.132 * 10²⁷ kg