Thursday HR Diagram Work

What does the Hertzsprung-Russell Diagram plot stars based on?

• Mass and size

• Absolute brightness and surface temperature

• Distance from Earth and age

• Color and speed

Answer explanation

The Hertzsprung-Russell Diagram plots stars based on their absolute brightness and surface temperature, allowing astronomers to understand their evolutionary stage and classify them into different types.

On the Hertzsprung-Russell Diagram, where are the main sequence stars primarily located?

• Along a band that runs from the top left to the bottom right

• Clustered at the top right corner

• Scattered randomly throughout the diagram

• Grouped at the bottom left corner

Answer explanation

Main sequence stars are primarily located along a band that runs from the top left to the bottom right on the Hertzsprung-Russell Diagram.

According to the Hertzsprung-Russell Diagram in your notebook, where is the Sun located?

• In the white dwarf region

• In the supergiant region

• On the main sequence

• In the giant branch region

Answer explanation

The Sun is located on the main sequence according to the Hertzsprung-Russell Diagram in the notebook.

Which of the following is the best explanation for the difference in color of two bright stars in a constellation, where one appears red and the other appears blue?

• The blue star must be moving toward Earth and the red star away from Earth.

• The red star must be moving toward Earth and the blue star away from Earth.

• The red star must have a greater surface temperature compared to the blue star.

• The blue star must have a greater surface temperature compared to the red star.

Answer explanation

The blue star appears blue because it has a greater surface temperature compared to the red star.

What is a limitation of using apparent magnitude rather than absolute brightness when measuring the brightness of a star?

• Apparent magnitude does not use the star's color or temperature.

• Apparent magnitude is only theoretical, thus its value cannot be directly measured with equipment.

• Apparent magnitude does not take into account the fact that not all stars are the same distance from Earth.

• Apparent magnitude is only on a comparative scale that determines how bright a star looks from a theoretical distance of 32 light-years from Earth.

Answer explanation

Apparent magnitude fails to consider varying distances of stars from Earth.

Which of the following statements is NOT true regarding main sequence stars?

• Red giant stars are part of the main sequence group.

• Most stars visible from Earth are main sequence stars.

• As surface temperature increases, absolute brightness increases.

• Main sequence stars are primarily composed of hydrogen and helium gas.

Answer explanation

Red giant stars are not part of the main sequence group.

Which of the following statements is true about the relationship between galaxies and stars?

• A galaxy contains many stars.

• A star contains many galaxies.

• A star contains only one galaxy.

• A galaxy contains only one star.

Answer explanation

A galaxy contains many stars.

NGC 1232 is a spiral galaxy about twice the size of our Milky Way Galaxy. It is located about 100 million light-years from Earth. Which of the following best explains why the physical properties of these two galaxies are similar?

• The temperatures of the stars within each galaxy are all identical.

• The two galaxies have the same shape and both orbit the same star.

• The two galaxies formed from the same materials and in the same way.

• All of the stars making up each galaxy are at the same stage of their life cycles as the Sun.

Answer explanation

The physical properties of NGC 1232 and the Milky Way are similar because they formed from the same materials and in the same way.

Due to the size of the Universe and the number of galaxies and stars in it, scientists must devise indirect ways to study it. Which of the following represents the best way for scientists to study the Universe?

• Scientists should create a graph showing a comparison of the relative sizes of all the galaxies and stars.

• Scientists should develop a gridded map and then number the known galaxies and stars and record their locations.

• Scientists should build a physical model that demonstrates the relative sizes and locations of all known galaxies and stars.

• Scientists should make a computer model of known galaxies and stars that allows for unknowns and modify it as new discoveries are made.

Answer explanation

The best way for scientists to study the Universe is by making a computer model of known galaxies and stars that allows for unknowns and modifying it as new discoveries are made.

Tags

NGSS.HS-ESS1-4

NGSS.HS-ETS1-4