HR Diagram 2

Front

What is the HR Diagram?

Back

The HR Diagram (Hertzsprung-Russell Diagram) is a scatter plot of stars showing the relationship between their absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.

Front

What spectral class is the sun classified in?

Back

The sun is classified as a main-sequence star in spectral class G.

Front

What is a main-sequence star?

Back

A main-sequence star is a star that is in the stable phase of its life cycle, where it fuses hydrogen into helium in its core.

Front

What are the characteristics of spectral class O stars?

Back

Spectral class O stars are very hot (over 30,000 K), very bright, and are typically blue in color.

Front

How do main-sequence stars in spectral class M compare to those in spectral class B?

Back

Main-sequence stars in spectral class M are cooler and less bright than those in spectral class B.

Front

What is luminosity in the context of stars?

Back

Luminosity is the total amount of energy emitted by a star per unit time, often compared to the sun's luminosity.

Front

What is the temperature range for spectral class K stars?

Back

Spectral class K stars have temperatures ranging from about 3,900 K to 5,200 K.

Front

What is a giant star?

Back

A giant star is a star that has expanded and cooled after exhausting the hydrogen in its core, making it larger and more luminous than a main-sequence star of the same temperature.

Front

What is a supergiant star?

Back

A supergiant star is an extremely large star that is more massive than a giant star and has a very high luminosity.

Front

What does it mean for a star to be brighter than the sun?

Back

A star is considered brighter than the sun if it has a higher luminosity than the sun, meaning it emits more light and energy.