42 terms

Astronomy Study Packet #2

What color will a star with a surface temperature of 5000-6000 K?
Mass of star can be determined by...
binary star systems
Parallax star angle
the closer the star the larger the parallax angle
How long is a light year?
9.5 trillion miles
What does not affect the apparent brightness of a star from earth?
how old the star is
Absolute magnitude
a measure of the amount of light that a star actually emits
Apparent magnitude
the brightness of a star when viewed from Earth
Hertzprung-Russel diagram shows...
the relationship between temperature and absolute magnitude
90% of stars on the Hertzprung-Russel diagram are...
main sequence stars
Before a star is born it is a...
cool, dark nebula
A star is born when......
a protostar reaches a temperature high enough for nuclear fusion to begin
What life cycle stage will the sun enter next?
red giant stage
What will be the final stage of our sun?
black dwarf stage
All stars eventually do what?
collapse into a white dwarf
What remains after a low-medium mass star dies?
white dwarf
Milky way nucleus dimensions
100,000 wide
10,000 light years thick
Where is our sun positioned in the milky way?
within one of the spirals about 30,000 light years away form the nucleus
60%of all known galaxies are classified as...
spiral galaxies
How do we know the universe is expanding?
red shift of distant galaxies
The universe began as what? (according to the big bang theory)
dense, hot, supermassive ball
What is evidence of the bug bang theory?
cosmic background radiation
Three properties of a star
temperature, color, mass
What can a star's color tell about the star?
It's approximate temperature
Binary Stars
stars pulled together by gravity used to determine mass
the apparent change in position of a star when seen from opposite sides of the Earth's orbit
Nearby stars have what?
Larger angles than distant stars
Parallax angles of distant stars are...
Too small to measure
How many star's parallax angles have been found?
only a few thousand of the closest stars
Blue stars
Red stars
Yellow stars
have medium temperature
a group of stars that forms a shape or pattern named to honor mythological characters
Emission Nebulae
hydrogen gas is ionized by the energy of nearby stars and glows by florescence
Absorption Nebulae
made of dense clouds of interstellar dust
All stars eventually become...
a white dwarf, neutron star, or black hole
Three types of galaxies
spiral, elliptical, irregular
Low mass stars stages
Nebula, protostar, main sequence star, white dwarf, black dwarf
Medium mass stars stages
Nebula, protostar, main sequence star, red giant, planetary nebula, white dwarf, black dwarf
Massive stars stages
Nebula, protostar, main sequence star, red supergiant, supernova explosion, black hole, neutron star
How does the red shift work?
light waves are "stretched", which shows that earth and the source are moving away from each other
Stages the sun will go through and has gone through
dust and gasses, main sequence star, red giant stage, planetary nebula, white dwarf
3 factors that define a star's apparent brightness
age, distance from earth, actual magnitude