What is a star? Chapter 16, lesson 2 5th grade science

1. What is a star?
Lesson 2

2. Stars
• Gigantic balls of
very hot gases that
give off
electromagnetic
radiation

3. • There are many
different sizes and
colors of stars.
• A star’s color
relates to how hot it
is…
– Red stars are coolest
– Orange and yellow
– White or blue-white
stars are the hottest

4. The Sun
• An average size star
• Closest to the Earth
• Brightest star in the
sky
• Enormous amounts
of light and heat
energy

5. Short Review…
1. Which star is hotter, a yellow star or a
white star?
2. What star is the closest to the Earth?

6. • The Sun is a
fiery ball of hot
gases with no
hard surfaces.
• The Sun’s
layers include
the
photosphere,
the
chromosphere,
and the corona.

7. The Explosive Sun
• The part of the Sun
that gives off the light
we see is called the
photosphere.
– It is the lowest layer of
the Sun’s atmosphere.
• The layer above the
photosphere is the
chromosphere.
• The outermost layer
is called the corona.

8. Sunspots
• Dark spots on the
face of the Sun
• The size of Earth or
larger
• Sunspots occur in the
Sun’s photosphere.
• The number of
sunspots changes in
cycles of about 11
years.

9. Solar Eruptions
• Linked to the sunspot
cycle:
– Solar Flare
• Parts of the
chromosphere erupt like
a volcano
• Can last from minutes to
hours
• May interrupt radio
communications on
Earth
– Prominence
• Ribbons of glowing gas
• Can last from minutes to
months

10. What is a Light-Year?
• The distance light
travels in one year,
5,880,000,000,000
miles

11. Short Review…
1. How long do solar flares last?
 from minutes to hours
1. Name two solar eruptions.
 Solar flares
 prominences

12. The Life of Stars
• A star is born in a cloud of gas and dust
called a nebular
• A star dies when it runs out of fuel—
hydrogen.
https://www.youtube.com/watch?v=80eMTnnLjhs