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Astronomy Year / Week 09 / Monday
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Week 09 · Star Colors and Brightness

Monday

Stars come in colors
// Hot stars, cool stars, near and far
⏱ about 15 min

Monday: Stars come in colors

Rocket remembers red Betelgeuse and blue Rigel. "Why are they different colors?"

Raven looks at the two stars. "What do you notice? Is it about heat?"

Nova glows blue, then red. "Hint: color can tell you about heat."

Color shows heat

Stars have different colors.

Hotter stars look blue or white.

Cooler stars look orange or red.

Even the cooler stars are very, very hot.

Star colorHot or cooler?
BlueHottest
WhiteHot
OrangeCooler
RedCoolest
HOT OR COOL?
  • Read the question.
  • Tap your answer.
A star looks blue. Is it hotter or cooler?
A star looks red. Is it hotter or cooler?
HOTTEST TO COOLEST
  • Tap a card.
  • Then tap its spot.
1Hottest
2Hot
3Cooler
4Coolest

Our Sun is a star too

The Sun is a hot, glowing ball of gas.

It is made mostly of hydrogen and helium.

It is our closest star.

Never look at it!

Safety first
Never look at the Sun.
Not with sunglasses. Not with binoculars. Not with a telescope.
The Sun can hurt your eyes very fast.
STAR HEAT
  • Read the question.
  • Tap your answer.
Which star color is the hottest?
Which is cooler, an orange star or a white star?
Are cooler stars cold like ice?
What is the Sun mostly made of?
Color factTrue or false?
Blue stars are hotter than red stars.?
Red stars are the hottest.?
White stars are hot.?
Look at the Sun to learn about it.?
WHY THIS EXERCISEColor is a clue to a star's heat.
Try it
Find crayons in blue, white, orange and red.
Make four stars, one in each color.
Put them in a row from hottest to coolest.
Make four stars from hottest to coolest. Label each one.

Great sorting! Tomorrow we match real stars to their colors.