Barnards star with the largest known proper motion 103577 p

Barnard\'s star, with the largest known proper motion = 10.3577 per year and the fourth-largest parallax angle = 0.54901. In the spectrum of Barnard\'s star, the Ha absorption line is observed to have a wavelength of 6560.34A when measured from the ground.

A). determine the radial velocity of Barnard\'s star

Solution

The transverse velocity is,

d = 1/p =1/0.54901 = 1.8214 parsecs = 5.620 X 10¹⁶ m/s