Observable

Formula

Parameters needed

to be measured

Constant

needed

Orbital time

$GM=\frac{4{\pi }^2{R}_2^3}{T^2}$

R₂, T

gravitational acceleration

$GM=\frac{2H{R}_1^2}{T_b^2}$

H, R₁, T_b

Light bending

$GM=\delta \frac{R{c}^2}{4}$

δ, R

c

Gravitational redshift

$GM=zR{c}^2$

z, R

c