Question

As viewed from a planet in a circular orbit of radius 1 AU around Alpha Centauri, the parallax angle of the Sun would be about:

A) 1 arc second
B) 1 arc minute
C) 1 degree
D) 1 radian
E) 1 parsec

Answer 1

From a planet in a circular orbit 1 AU from Alpha Centauri, the Sun's parallax would be close to 0.75 arcseconds, similar to Alpha Centauri's parallax from Earth.

Step-by-step explanation:

The parallax angle of the Sun as viewed from a planet in circular orbit of radius 1 AU around Alpha Centauri would be approximately the same as the parallax angle Alpha Centauri as seen from Earth, because the distance between our Sun and Alpha Centauri is similar to the distance from Alpha Centauri to the hypothetical planet. We know that Alpha Centauri has a parallax of roughly 0.75 arcseconds as measured from Earth. Therefore, when viewed from a planet at 1 AU from Alpha Centauri, the Sun would have a parallax angle close to 0.75 arcseconds. This is much smaller than 1 arcsecond, so the correct answer is A) 1 arc second.