Understanding Stars

Front

Huge celestial bodies made mostly of hydrogen and helium, capable of producing light and heat from nuclear fusion in their cores.

Back

Stars

Front

What is the nearest star to Earth?

Back

The Sun

Front

Two forces that keep the star stable.

Back

Gravity - squeezes it into a compact ball

Outward pressure - from nuclear fuel burning resisting the inward squeeze.

Front

What causes the formation of a planetary system around a star?

Back

Strong gravitational force

Front

How do astronomers classify stars?

Back

physical characteristics

(color, surface temperature, brightness, size, and composition)

Front

What does the color of a star indicate?

Back

Surface temperature

Front

A tool used in astronomy to measure the spectra produced by matter interacting with or emitting electromagnetic radiation.

Back

Spectroscopy

Front

What is the chemical composition of most stars?

Back

about 73% hydrogen, 25% helium, and 2% other elements

Front

This system classifies stars using letters O, B, A, F, G, K, and M.

Back

Morgan-Keenan (MK) system

Front

Hottest type of star in the MK system

Back

O stars