A parsec is
I. a unit of length used in astronomy
II. 2.06 × 105 AU
III. the distance to an imaginary star whose stellar parallax is one arc second
IV. 3.26 light years
V. the longest unit of length in astronomy
A)I, II, V
B)II, IV
C)I, III, IV, V
D)I, II, III, IV, IV

Question

Quizplus · Accepted Answer

A parsec is indeed a unit of length used in astronomy (I), equivalent to approximately 2.06 × 10^5 astronomical units (AU) (II), defined as the distance to an object with a parallax angle of one arcsecond (III), and is about 3.26 light years (IV). It is not the longest unit of length in astronomy, as there are larger units such as the megaparsec used for galactic and intergalactic distances.

A Parsec Is I. a Unit of Length Used in Astronomy