Astronomical Distances and Units

The video tutorial explains the concept of a Parsec, an astronomical unit of distance. It begins by defining Parsec as the parallax of one arc-second and describes it as the longest unit of length. The tutorial explains how the distance between the Earth and the Sun, known as an astronomical unit, is used to understand Parsec. It illustrates how angles change with distance and provides examples of distances and corresponding angles. The video defines 1 Parsec as the distance at which the Earth's orbital radius subtends an angle of 1 arc-second, equivalent to 30.86 trillion kilometers or 3.26 light years. A mathematical explanation is provided, and the video concludes with a summary of the key points.

What does the term 'Parsec' stand for?

• Parallel arc-second

• Perpendicular arc-second

• Parallax of one arc-second

• Parabolic arc-second

What is the average distance between the Earth and the Sun called?

• Light year

• Kilometer

• Astronomical unit

• Parsec

At what distance from Earth does an object create a 60-degree angle?

• 149.6 million kilometers

• 8.57 billion kilometers

• 259 million kilometers

• 86 million kilometers

How far must an object be to create an angle of 1 arc-second?

• 149.6 million kilometers

• Some trillion kilometers

• 514 billion kilometers

• 86 million kilometers

What is the equivalent of 1 parsec in light years?

• 4.26 light years

• 3.26 light years

• 2.26 light years

• 1.26 light years

What is the mathematical relationship used to calculate 1 parsec?

• tan theta = distance s-e / distance o-e

• cot theta = distance s-e / distance o-e

• cos theta = distance s-e / distance o-e

• sin theta = distance s-e / distance o-e

What is the distance s-e in the calculation of 1 parsec?

• 8.57 billion kilometers

• 149.6 million kilometers

• 86 million kilometers

• 259 million kilometers

What is the primary use of the parsec unit in astronomy?

• To measure the brightness of stars

• To measure the speed of light

• To measure the size of planets

• To measure distances to near Earth stars

How many meters is 1 parsec equivalent to in the SI method?

• 3.086 x 10^15 meters

• 3.086 x 10^16 meters

• 3.086 x 10^17 meters

• 3.086 x 10^18 meters