A star has a parallax of .19 arc seconds. The stars has a proper motion of 7.2 arc seconds per years and a radial velocity of +260 km/s. How do you find the Tangential Velocity and the total velocity of the star?

1 Answer
Feb 1, 2018

Answer:

#v_t=180km# #s^(-1)#

#v~~316km# #s^(-1)#

Explanation:

#v_t# is given by the formula: #v_t=(4.75mu)/p#, where:

  • #mu# = proper motion (arc seconds per year)
  • #p# = parallax (arc seconds)

#v_t=(4.75*7.2)/0.19=180km# #s^(-1)#

#v=sqrt(v_t""^2+v_r""^2)#

#color(white)(v)=sqrt(180^2+260^2)#

#color(white)(v)~~316km# #s^(-1)#