Question

If a star is $5.2\times {10}^{16}m$ away. What is the parallax angle in degrees?

• A. $1.67\times {10}^{-4}$ degrees
• B. $1.67\times {10}^{-5}$ degrees
• C. $0.67\times {10}^{-4}$ degrees
• D. $2.3\times {10}^{-4}$ degrees

Answer 1

Answer: (A)

$1.67\times {10}^{-4}$ degrees

Given : $1$ AU $=1.5\times {10}^{1}1$ m $d=5.2\times {10}^{15}$ m

Parallax angle: $\alpha =\frac{1AU}{d}=\frac{1.5\times {10}^{11}}{5.2\times {10}^{16}}=0.288\times {10}^{-5}$ radians

$⟹$ $\alpha =\frac{180}{\pi }\times 0.288\times {10}^{-5}=1.67\times {10}^{-4}$ degrees