Transcript 21-2 - Laconia School District

Chapter 21. Section 2.
Characteristics of stars.
Betelgeuse is as large as Saturn's
orbit…
Explain how stars are classified.
• Stars are classified by color, temperature,
size, composition, brightness and spectra.
Describe how astronomers measure
distances to stars.
• Astronomers measure distance from a star
with a parallax. A parallax is a apparent
change in position of an object when you
look at it from different places. This means
that if you stick your thumb out and close
one eye, it will be in a spot. Then close
that eye and open the other eye and it will
change positions. This is an example of a
parallax.
Describe the H-R diagram, and explain how
astronomers use it.
• Super giants, Giants, Main sequence, White
dwarfs are parts of the main sequence. The
reddish star mean that it is the coolest star.
And the hottest star is the whitish bluish color.
The brightest stars are at the top of the
diagram and the dimmest stars are at the
bottom. The stars that look the brightest is
closest to the sun. It looks the hottest but it is
not. For example white dwarfs are very hot
but they don’t look it.
Parallax Activity.
H-R diagram
Parallax
This video is presented by
• Drew
• Jeremy
• Josh
People that Assisted in the project
Tori
Brock
Tristan