How many AU is the nearest star from earth?

Feb 7, 2016

$\approx 267$ thousand AU

Explanation:

Forgeting the Sun which is 1 AU from us, we have Proxima Centauri at 4.23 light-years from us.

4.23 light years is:

$4.23 y e a r \times 365 \cdot 24 \cdot 60 \cdot 60 \frac{\sec o n \mathrm{ds}}{y} e a r \times 300000 \frac{k m}{\sec o n d}$

$= 4.0 \times {10}^{13} k m$

$1 A U = 1.496 \times {10}^{8} k m$

So the distance of Proxima Centauri in AU is

$= \frac{4.0 \times {10}^{13}}{1.496 \times {10}^{8}}$

$\approx 267$ thousand AU