The ________ the parallax angle, the __________ the star.

What is the definition of a parsec (pc)?

How much is one second of arc?

How do you calculate distance in parsecs?

Typically, what is the distance between neighbouring stars?

What does the luminosity of a star depend upon?

What do Cepheid variable stars do?

The _______ the period, the _______ the Cepheid.

How do astronomers estimate the distance to Cepheid variables?

What did telescopes reveal?

What else did telescopes reveal?

What was the main issue in the Curtis-Shapely debate?

What did Hubble's observations of Cepheid variables conclude?

What are intergalactic distances typically measured in?

How do you calculate the speed of recession (km/s) of a distant galaxy?

How do the motions of galaxies suggest that space itself is expanding?

How do scientists believe the world began?