What formula relates tangential velocity ($v_t$), proper motion ($ u$), and distance ($d$)?

Answer

$v_t$ = $ u$ d

The true tangential velocity of a star is directly proportional to both its observed proper motion and its distance from Earth, following a linear relationship where the velocity is the product of the other two variables.

What formula relates tangential velocity ($v_t$), proper motion ($
u$), and distance ($d$)?
measurementastronomyDistancestarmotion