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Astronomy Year / Week 08 / Thursday
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Week 08 · Orion the Hunter

Thursday

The Summer Triangle
// A winter giant and a summer triangle
⏱ about 15 min

Thursday: The Summer Triangle

Rocket is sad. "It is not winter. How can I find Orion?"

Raven points up on a warm night. "What do you notice right overhead?"

Nova draws three lines. "Hint: three bright stars make a big shape."

Three bright stars

The Summer Triangle is made of three bright stars.

Their names are Vega, Deneb and Altair.

It is high overhead on summer evenings.

In early fall, it is still high after dark.

You can see it even from a city.

StarIts star group
VegaLyra, the Harp
DenebCygnus, the Swan
AltairAquila, the Eagle

The Summer Triangle is an asterism.

Its three stars belong to three different star groups.

TRIANGLE CHECK
  • Read the question.
  • Tap your answer.
How many stars make the Summer Triangle?
Which star belongs to Lyra, the Harp?
Is the Summer Triangle an official constellation?
Triangle factTrue or false?
The Summer Triangle is high on summer evenings.?
Altair is in Aquila, the Eagle.?
You need a very dark sky to see the Summer Triangle.?
WHY THIS EXERCISEBright stars are easy to find, even from a city.

When to look up

Vega is overhead on July evenings.

In late summer and early fall, look around 9 at night.

Vega is nearly overhead then.

Find Vega, then look for the other two corners.

TRIANGLE PRACTICE
  • Read the question.
  • Tap your answer.
Which star belongs to Cygnus, the Swan?
Which star belongs to Aquila, the Eagle?
When is Vega overhead in the evening?
Can you see the Summer Triangle from a city?
FIND THE SUMMER TRIANGLE
  • Tap a card.
  • Then tap its spot.
1First
2Next
3Then
4Last
Try it
Lie on a blanket with a grown-up.
Pretend the ceiling is the night sky.
Point to three spots for Vega, Deneb and Altair.
Draw the Summer Triangle. Label Vega, Deneb and Altair.

You found a summer shape! Tomorrow we meet the Swan and the Harp.

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