Betelgeuse is 652 light-years away, and what is its parallax?

To solve the presented problem, we write down the horizontal parallax formula.

It looks like this:

D = RЗ / sin p,

where D is the distance to the star,

RЗ – the radius of the Earth, equal to 6371 km,

p is the angle from which the Earth’s radius is visible.

Let’s convert light years to kilometers:

652 = 9.46 * 10 ^ 12 * 652 = 6167.92 * 10 ^ 12 km.

Let us express the horizontal parallax from it:

sin p = RЗ / D.

Substituting the known values into the written formula, we get:

sin p = 6371 km / 6167.92 * 10 ^ 12 km ≈ 1.03 * 10 ^ -12.

Answer: 1.03 * 10 ^ -12.