For our periodical Flashcards
EARTH SCIENCE 1ST QUARTER
Largest object in our solar system
Sun
Huge luminous spheres of very hot gas (plasma)
Stars
What does stars release
Huge amounts of radiant energy (light) and thermal energy (heat)
Why does stars release thermal and radiant energy?
These energy is produced by a process called nuclear fusion
Involves combining several small nuclei into one large nucleus
Nuclear fusion
15,000,000°C, two hydrogen atoms fuse to form one helium
Nuclear fusion
44 main ways of classifying stars
Color, temperature, size, brightness
How do we classify stars by their color and temperature?
A star’s color is determined by its temperature; the coolest stars appear red; the hottest stars appear white-blue; medium stars appear yellow- orange
How does size help us classify stars?
Smallest: neutron stars (20km in diameter) small: white dwarf stars (earth-size - 12,200km)
Large: giant stars (10-100 x sun)
Largest: supergiants (100-300 x sun)
How does brightness help us in classifying stars?
How bright stars appears depends on how bright it truly is and its distance from earth
Brightness described in 2 ways
Apparent Brightness, Absulute brightness
Apparent brightness
Advantage:easy to measure
Disadvantage:not accurate
Absulute brightness
Advantage:very accurate
Disadvantage:must know distance
Unit used by astronomers to measure distance
Light year
In space, light travels in what speed?
300,000km per second
