Stars and Galaxies: What Are Stars?

The video tutorial explains that the Sun is the closest star to Earth and is central to our solar system. It appears brighter and larger due to its proximity. The Sun, like other stars, is a hot ball of gases and plasma, emitting heat and light energy through chemical reactions. Astronomers study stars by analyzing their light energy. Distances in space are measured in kilometers for nearby objects and light-years for distant ones. Light travels at 310,000 km/s, covering 9.5 trillion km in a year. Proxima Centauri, the closest star beyond the Sun, is 4.3 light-years away, while Rigel is 910 light-years away, meaning its light takes 910 years to reach Earth.

Which star is the closest to Earth, making it appear brighter and larger than others?

• The Sun

• Rigel

• Proxima Centauri

• Sirius

What analogy is used to explain why the Sun appears brighter and larger than other stars?

• A distant lighthouse

• A candle in the dark

• A glowing ember

• A flashlight held close

What are stars primarily composed of?

• Solid rock

• Metallic elements

• Liquid water

• Burning gases and plasma

What unit do astronomers use to measure distances to stars outside our solar system?

• Light-years

• Astronomical units

• Kilometers

• Miles

How far is Proxima Centauri from Earth in light-years?

• 4.3 light-years

• 1.3 light-years

• 40.3 light-years

• 10.3 light-years