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9th grade Read a Hertzsprung-Russell diagram worksheet

6 printable versionsBuilding Confidence10 questions · answer keyFree · no account

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Read a Hertzsprung-Russell diagram

Grade 9 Science Worksheet - Building Confidence

NameDate

Circle the best answer.

  1. On an H-R diagram, which side holds the hottest stars, by Ari's reading?

    • The bottom edge
    • The right side
    • The left side
    • The top edge

  2. What does the up-and-down axis of an H-R diagram show, by Bo's reading?

    • The star's age, as it travels up
    • Distance from Earth
    • Brightness compared with the Sun
    • Surface temperature

  3. Read this first

    Model stars (model data; Sun values from IAU)

    StarSurface temperature (K)Brightness (Sun = 1)
    A30,00010,000
    B9,90025
    C (Sun)5,8001
    D3,5000.01
    E3,600100,000
    G20,0000.01

  4. Star A is 30,000 K and Star D is 3,500 K. Which one sits farther left on the H-R diagram, by Kira's reading?

    • A, the hotter star
    • D, the cooler star
    • Neither; they line up one above the other
    • D, since it is dimmer

  5. What do all main-sequence stars have in common, by Jun's reading (NASA)?

    • They share one surface temperature
    • They are the same age
    • They are near the end of their lives
    • They fuse hydrogen into helium in their cores

  6. Model stars (model data; Sun values from IAU)

    StarSurface temperature (K)Brightness (Sun = 1)
    A30,00010,000
    B9,90025
    C (Sun)5,8001
    D3,5000.01
    E3,600100,000
    G20,0000.01

  7. Star E is 3,600 K with a brightness of 100,000. Which group is it in, by Luz's reading?

    • Red dwarfs, since cool stars are dim
    • Hot blue stars, top left
    • White dwarfs, bottom left
    • Supergiants, top right

  8. Star G is 20,000 K with a brightness of 0.01. Which group is it in, by Milo's reading?

    • Red dwarfs, since dim stars are cool
    • White dwarfs, bottom left
    • Blue main-sequence stars, since hot stars are bright
    • Supergiants, top right

  9. One red, one blue. Pia spots a red star and a blue star. Which has the cooler surface?

    • The blue star
    • The red star
    • Neither; color shows just size
    • The blue star, since blue looks cold

  10. Row of star dots from blue on the left to red on the right, with 5,800 K marked. The Sun's surface is about 5,800 K. Which color class fits it, by Ren's reading (NASA calls it a yellow dwarf)?

    • Red, the coolest
    • Yellow, between the blue and red stars
    • Green
    • Blue, the hottest

  11. Model stars (model data; Sun values from IAU)

    StarSurface temperature (K)Brightness (Sun = 1)
    A30,00010,000
    B9,90025
    C (Sun)5,8001
    D3,5000.01
    E3,600100,000
    G20,0000.01

  12. Star B has a brightness of 25. Compared with the Sun, it is what, by Tala's reading?

    • 25% as bright
    • 2.5 times brighter
    • 25 times brighter
    • 25 times dimmer

  13. Star D has a brightness of 0.01. Compared with the Sun, it is what, by Esme's reading?

    • 100 times brighter
    • 10 times dimmer
    • 100 times dimmer
    • 0.01 times hotter
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9th grade Read a Hertzsprung-Russell diagram worksheet – printable
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About this worksheet

Read a Hertzsprung-Russell diagram. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can read both axes of an H-R diagram (hot on the left, brightness up on a ×10 scale) and place the main sequence, giants, supergiants and white dwarfs.
  • I can link star color to temperature and use brightness = radius² × temperature⁴ to explain cool-but-bright giants and hot-but-dim white dwarfs.
  • I can explain that mass, not age, sets a star's place on the main sequence, and trace the Sun's future path.

Standard: supports HS-ESS1-3

Words to know

H-R diagram: A graph of star brightness against surface temperature

luminosity: How much light a star gives off, compared with the Sun

main sequence: The band where stars fuse hydrogen in their cores

supergiant: A huge, very bright star

white dwarf: A tiny, hot, dim leftover core

log scale: An axis where each gridline is 10 times the last

Common mistakes

Your child read the H-R diagram's axes the wrong way. Surface temperature falls from left to right, and brightness rises upward.

Your child assumed brighter means hotter and dimmer means cooler. A star's brightness also depends on its size: giants are cool but bright, white dwarfs hot but dim.

Your child thought stars travel along the main sequence as they age. A star's mass sets its place on the main sequence; it leaves the band when its core hydrogen runs out (NASA).

Questions parents ask

What is the most common mistake with read a hertzsprung-russell diagram?

Your child read the H-R diagram's axes the wrong way. Surface temperature falls from left to right, and brightness rises upward.

Are these 9th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

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