H-R diagram

Analyzing HR

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Multiple Choice

Some students used records from the U.S. Naval Observatory to make the table below of the percent of the moon that was visible on each night in January 2011.

Based on these data, what part of the lunar cycle occurred between January 5 and January 7?

• Waxing crescent moon

• Waning crescent moon

• Full moon

• New moon

Multiple Choice

The diagram below shows four positions in Earth’s orbit around the sun.

The Northern Hemisphere experiences the beginning of spring when Earth is in —

• 1

• 2

• 3

• 4

Multiple Choice

What force causes Venus to travel along a curved path instead of moving in a straight line as indicated by the dashed line in the diagram?

• Electromagnetic attraction between the sun and Venus

• Gravitational attraction between the sun and Venus

• Electromagnetic attraction between Mercury and Venus

• Gravitational attraction between Mercury and Venus

Open Ended

What are some things you notice about this chart?

Hertzsprung- Russell Diagram

Size

Luminosity

Color

Temperature

Open Ended

What kind of chart is this? Where have you seen this before?

Luminosity

Brightness is similar to size.

The bigger the brighter.

Size

Multiple Select

Going up the Y-axis, what two things increase in the HR diagram?

• Color

• Size

• Temperature

• Luminosity

Color (Temperature)

Left is Hot
Right is Cool

Red- 3000
Orange- 4000
Yellow- 6000
White- 10,000
Blue- 25,000

Multiple Select

Left to Right on the X-axis, what two things change in the HR diagram?

• Color

• Size

• Temperature

• Luminosity

Multiple Choice

On which side of the HR diagram can the hottest stars be found?

• Left

• Right

• Middle

• Top

Multiple Choice

On which side of the HR diagram can the coolest stars be found?

• Left

• Right

• Middle

• Top

Multiple Choice

On the HR diagram which color is the hottest star found in the universe?

• Blue

• Yellow

• White

• Red

Multiple Choice

On the HR diagram which color is the coolest star found in the universe?

• Blue

• Yellow

• White

• Red

Multiple Choice

Which group of stars would our sun be found?

• Giants

• Supergiants

• Main Sequence

• White Dwarfs

Apparent vs Absolute Magnitude

Apparent

How bright the star looks
from Earth.

Absolute Magnitude

How bright the star actually is
in space.

The Sun. It is closer that all other stars, but closer to Earth

Open Ended

Explain why the sun is the largest star that we can see.

Multiple Choice

Which group of stars could be found here?

• Giants

• Supergiants

• Main Sequence

• White Dwarfs

Multiple Choice

Compared to our sun, which group of stars would be hotter and dimmer?

• Giants

• Supergiants

• Main Sequence

• White Dwarfs

Multiple Choice

Compared to our sun, which group of stars would be hotter and brighter?

• Giants

• Supergiants

• Main Sequence

• White Dwarfs

Multiple Choice

Compared to our sun, the other star is.....

• Hotter and Dimmer

• Cooler and Dimmer

• Hotter and Brighter

• Cooler and Brighter

Multiple Choice

Which group would this other star be found?

• Giant

• Main Sequence

• Supergiant

• White Dwarf

Multiple Choice

Compared to our sun, the other star is.....

• Hotter and Dimmer

• Cooler and Dimmer

• Hotter and Brighter

• Cooler and Brighter

Multiple Choice

Which group would this other star be found?

• Giant

• Main Sequence

• Supergiant

• White Dwarf

Multiple Choice

Compared to our sun, the other star is.....

• Hotter and Dimmer

• Cooler and Dimmer

• Hotter and Brighter

• Cooler and Brighter

Multiple Choice

Which group would this other star be found?

• Giant

• Main Sequence

• Supergiant

• White Dwarf

Multiple Choice

Compared to our sun, the other star is.....

• Hotter and Dimmer

• Cooler and Dimmer

• Hotter and Brighter

• Cooler and Brighter

Multiple Choice

Which group would this other star be found?

• Giant

• Main Sequence

• Supergiant

• White Dwarf

Multiple Choice

Based on this diagram, which type of stars would belong to spectral class M and have the highest luminosity?

• Main-sequence stars

• Giants

• White dwarfs

• Supergiants

Open Ended

Describe how you would explain to someone how to read an H-R Diagram