HR Diagram

Front

What is the H-R Diagram?

Back

The H-R Diagram (Hertzsprung-Russell Diagram) is a graph that shows the relationship between a star's surface temperature and its absolute magnitude (luminosity).

Front

What does a star's temperature determine?

Back

A star's temperature determines its color.

Front

What type of star is cooler and dimmer than the Sun?

Back

White Dwarfs are cooler and dimmer than the Sun.

Front

What additional information does the H-R Diagram provide besides luminosity and temperature?

Back

The H-R Diagram also provides information about a star's size, color, and elemental makeup.

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. An example is a star with a temperature of 10,000 K and a luminosity 5000 times greater than the Sun.

Front

What are the axes of the H-R Diagram?

Back

The vertical axis represents luminosity (absolute magnitude), while the horizontal axis represents surface temperature (in Kelvin).

Front

What is the significance of a star's color?

Back

A star's color indicates its surface temperature, with blue stars being the hottest and red stars being the coolest.

Front

What are supergiants?

Back

Supergiants are massive stars that have expanded and are among the largest stars in the universe, often having high luminosity.

Front

What is a red giant?

Back

A red giant is a star that has expanded and cooled after exhausting the hydrogen in its core, resulting in a cooler temperature and a reddish color.

Front

What is luminosity?

Back

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