Download Characteristics of Stars

Characteristics of Stars
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Constellations
• Today we use constellations to find stars
in the night sky.
Classifying Stars
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Color
Temperature
Size
Composition
Brightness
Star Temperature
• Surface Temperature = Color
Blue-white
Hottest
White
yellow
*Sun
orange
red
coolest
Compare the sizes of Stars
• Our Sun is a medium sized Star
What is a Star?
• Hot glowing masses of Gases
• Composition: Mostly Hydrogen and Helium
What makes a Star Shine?
• The fusion of Atoms
Hydrogen atoms fusing to form Helium
releasing Heat, Light and energy
• Astronomers use a Spectroscope to determine
the composition of a Star
Star Brightness (magnitude)
• Absolute Magnitude: the “Real” brightness
of the star. How much light it really gives
off.(Need to know the distance to the Star)
• Apparent Magnitude: How bright the star
appears to be.
Star Distance
• Measured in Light-Years
• Light-Year: The distance light travels
in a year. (9.5 million million Kilometers)
5.87849981 × 1012 miles (6 trillion miles)
• Speed of light: 186,000 Miles/second
300,000 Kilometers/Second
Finding the Distance to Stars
• Parallax: The “apparent “ Shift that a star
has over a period of Time
• The closer the object, the more it will shift
position in the sky
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Background Star
H-R Diagram
Hertzsprung-Russell
• Compares star temperature and Brightness
Star Types