Types of Stars
Vocabulary
Charts
Analysis
Life Cycle
100
What is a neutron star?
a dense core of neutrons that remains after a Supernovae
100
What is Luminosity
the true brightness of an object
100
What does the x-axis on a H-R diagram display?
decreasing temperature
100
During a star's life cycle, it can be a white dwarf, black hole or a neutron star. What determines what the star will become?
The star's mass at birth
100
Where do stars first form? How do they form?
They form deep inside clouds of gas and dust (nebulae).
Gravity causes the densest parts to collapse, forming regions called protostars.
200
What is a black hole?
an object whose gravity is so great that no light can escape
200
What is a Hertzsprung-Russell Diagram?
a graph that plots the luminosity versus the temperature of stars
200
What does the Y-axis of the H-R diagram display?
Increasing luminosity (light)
200
What is the coolest red star according to the diagram?
Barnard's star
200
What happens at the protostar stage?
The protostars continue to contract, pulling in surrounding gas until their cores are hot and dense enough for nuclear fusion to take place.
300
What is a White Dwarf?
a hot, dense, slowly cooling sphere of carbon
300
What are the layers of a star in order from outermost layer to innermost layer?
Corona, Chromosphere, Photosphere, Convection zone, Radiative zone, and core
300
What colors represent are the coolest v. the hottest stars on an H-R chart?
Cooler stars (like red giants) are red in color.
The hottest stars are blue.
Stars that are in the middle can be either white or yellow.
300
The ________ of star determines it's fate at the end of its life cycle.
Mass
300
When does a star become a Main-Sequence Star?
when the star begins to fuse hydrogen into helium in it's core
400
What is a Supernovae?
an enormous explosion that destroys a star.
400
What is a red giant?
a dying star that has expanded and cooled to a red color
400
What is the hottest Blue star on the diagram below?
Zeta Eridani
400
What will be the final stage of our sun's life cycle?
the sun will become a white dwarf
400
When does a star leave the Main-Sequence Star category on an H-R Diagram?
when the star's hydrogen supply is nearly gone. It then moves into the next phase.
500
What is a (planetary) nebula?
A cloud of gas and dust created by a dying, average-sized star
500
What is nuclear fusion?
atoms collide and nuclei stick together
500
What is the brightest yellow star on the H-R diagram below?
North Star (Polaris)
500
How would the life cycle of the Sun be different if it were more massive?
it would explode instead of becoming a white dwarf
500
What are the THREE possible ways a star can end it's life cycle? [explain what happens to stars with a larger mass (massive stars) and stars with a smaller mass (average star)]
Massive stars experience a supernova, and either become a black hole or a neutron star.
Average stars become a white dwarf after all of the helium in their core is gone. They DO NOT experience a supernova.