The Sun is about 8000 parsecs from the center of the Milky Way Galaxy, while the Hipparcos satellite measured parallaxes to an accuracy of about 0.01 arcseconds. How far toward the galactic center could astronomers see with Hipparcos (ignoring galactic dust and other obstacles)?

Question

Quizplus · Accepted Answer

The distance in parsecs can be calculated as 1/parallax in arcseconds. With a parallax accuracy of 0.01 arcseconds, the maximum distance measurable is 1/0.01 = 100 parsecs. Since the Sun is about 8000 parsecs from the center, Hipparcos could see about 1/80 of the way to the center.

The Sun Is About 8000 Parsecs from the Center of the Milky