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45 Cards in this Set

  • Front
  • Back
What is a star?
object in space made of burning gasses which produce their own light and heat
What is Nuclear Fusion?
the process by which suns produce light and heat. (2 hydrogen atoms combine to form 1 helium atom)
What are the 3 types of stars?
Main Sequence- hottest and largest (generate the most light, sun)
White Dwards- very hot but not bright
Giants and Super Giants- exteremly bright but not hot
How old is our sun?
4.6 billion years old
How much longer will our sun burn?
around 5 billion years
What type of star is the sun?
Main Sequence star
What is the diameter of the sun?
1.4 km
What is the compostion of our sun?
92% hydrogen and 8% helium
What is a galaxy?
a large group of stars, gas and dust held together by gravity
Gradually what is happening to galaxies?
they are spreading apart
What are the 4 major types of galaxies?
Elliptical- Some elliptical galaxies are nearly circular in shape. SOme elliptical galaxies are extremely stretched out, flattened, or clongated.
Spiral: galaxies with bright nuclei also had "arms" spiraling out from the middle. (Barred Spiral)
Irregular: Galaxies that cant be classified as either spiral or elliptical.
What did Edwin Hubble Notice?
-galaxies were getting farther apart
-universe is constantly expanding in all directions
What is the Big Bang Theory?
10-20 billion years ago tremendous explosion started the expansion of the universe from single point
What is the Copernican Theory?
The universe appears the same in all directions
In 1927 what did the Blgian Priest Georges Lemaitre first propose?
that the universe began with an explosion of a primeval atom.
What is hubble?
-galaxies spreading apart uniformily in every direction
-speed of expansion proportional to distance away
List the 7 stages in the birth of a star?
-formed with a cloud of hydrogen gas that collapses
-when it becomes hot enought to burn nuclear fuel, proudces large amounts of heat and radiation
-after there is no more nuclear fuel, the star enlarges and the core contracts
-turns into a giant star
-after exploding the giant star with turn into a black dwarf, neutron star, or black hole, depending on size
At which temperature must the core of a star reach for nuclear fusion to begin?
27,000,000 degrees
How does the size of a star affect the lifespan of the star?
the larger the star the shorter the life span, the smaller the star the longer the life span.
What are the 3 fates of a star?
Either it becomes a black dwarf, neutron star, or black hole
The fate of a star depends on how?
massive it is
What is the HertzSprung Russel Diagram?
graph that shows the color and brightness of stars
What 5 characteristics are plotted on the HertzSprug Russel Diagram?
Five characteristics are; Magnitude, Luminosity, Spectral Class, Temperature, and Size.
What are the three types of main sequence stars?
The three main types of main sequence stars are; Supergiants, white dwarfs, and Black dwarfs.
What are old, large stars classified as? What are the three types of these stars?
Old, Large stars are classifed as Giant and Supergiant Stars. Three types of these stars are Red Giants, SuperGiant and Blue Giant.
What are the 4 types of virtually dead stars?
The four types of virtually dead stars are; White dwarfs, Brown dwarfs, Neutron Stars and Pulsars.
In a spiral galaxy, where are the old stars located? Where are the young stars located?
The old stars are located in the central bulge. The young stars are located in the spiral Arm and the dust and gas lit by UV light.
White types of stars are at the center of an elliptical galaxy?
Red giant stars are the center of an elliptical galaxy.
What are two theories on how irregular galaxies form?
-when galaxies collide or come close to one another and their gravitational forces work together.
-another source of irregular galaxies may be very young galaxies that have not fully grown into the possible geometric shape.
What is a black hole?
the evolutionary endings of stars that are at least 10 to 15 time larger than the sun.
What is the Swartzchild radius?
The Swartzchild radius is a radius that the escapes speed is equal to the speed of light and once light passes through the radius, it cannot escape.
What is a constellation?
A constellation is a group of stars that, when seen from earth form a pattern.
How many constellations are there?
Are the big and little dipper constellations? If not what are they?
No, the Big and Little Dipper are asterisms, which are smaller apparent star patterns that are in a constellation.
What is the zodiac?
The Zodiac is a band of 12 constellations along the ecliptic.
What is the difference between a seasonal constellation and a circumpolar constellation?
Circumpolar constellations are constellations that never rise or set. The rest of the constellations are divided into seasonal constellations.
Does luminosity on a HertzSprung Russel Diagram go up or down?
Does temperature on the x axis of a HertzSprung Russel Diagram increase left or right?
Our sun would fit into what color main sequence star?
Yellow main sequence star- yellow dwarf
What are the 2 layers of our sun? And Describe Each
Core (middle of the sun)- 27,000,000 degrees F

Photosphere (outer visible layer, surface)- 11,000 degrees F,
What are the 3 events that can take place on the photosphere?
- sun spots(cooler region of the photosphere cuased by strong magnetic fields,
-solar flares (explosions of hydrogen), and
-solar promeninces(arcs and loops of gas that erupt from the surface of the sun).
Where are we located?
In the Milky Way, in an arm because we are young
Black holes have zero?
What are the two myths that arent true?
suck things in
and transport to different dimensions
Black holes are so powerful that they?
have a lot of gravity because they dont let any light out