Unit 4: Our Universe Retake

Front

What is the primary composition of all stars?

Back

All stars are made of the same basic materials, primarily hydrogen and helium.

Front

What classification is given to a star with a luminosity of 10^6 L_sun and a temperature of 20,000 K?

Back

Blue Giant

Front

What are the three main types of galaxies?

Back

Spiral, elliptical, and irregular.

Front

What type of galaxy is Earth’s galaxy?

Back

Earth's galaxy is a spiral galaxy.

Front

What unit of measurement do astronomers use to express the size of the universe?

Back

Light years.

Front

What is the relationship between a galaxy and the number of stars it can contain?

Back

A galaxy can contain up to a trillion stars.

Front

In the context of the universe, what is a solar system?

Back

A solar system is a collection of celestial bodies, including a star and the objects that orbit it.

Front

What is the difference between a star and a galaxy?

Back

A star is a luminous celestial body, while a galaxy is a massive system that contains many stars, gas, dust, and dark matter.

Front

What does the Hertzsprung-Russell Diagram represent?

Back

The Hertzsprung-Russell Diagram classifies stars based on their luminosity and temperature.

Front

What is the significance of the central disc and bright arms in a spiral galaxy?

Back

They indicate the structure and rotation of the galaxy.