space 1
What is stellar evolution?
The process by which a star changes over the course of time.
what's the longest phase of a star's life ?
the main-sequence
What color do hotter stars appear on the H-R diagram?
BLUE
what is the role of nuclear fusion in a star's life cycle ?
to generate energy
What is a nebula?
A cloud of gas and dust in space.
What is the primary process through which stars produce energy?
hydrogen fusion
What color do cooler stars appear on the H-R diagram?
RED
what element is primarily formed from the fusion of hydrogen nuclei ?
helium
What is nuclear fusion?
the process where two light atomic nuclei combine to form a heavier nucleus.
what is a supernova ?
a massive explosion that occurs at the end of a star's life cycle
Which axis of the H-R diagram represents a star's brightness?
The vertical axis
Where does fusion occur in stars?
In stars, hydrogen nuclei fuse to form helium through nuclear fusion.
What elements are fused in main sequence star ?
hydrogen into helium
what is luminosity ?
the total amount of energy a star emits.
What does the Hertzsprung-Russell (H-R) diagram plot?
brightness and temperature.
what is the final stage of a dying star ?
black dwarf
Stars are massive celestial bodies that produce energy, what is this process called ?
nuclear fusion
What happens to hydrogen nuclei in the core of a star during fusion?
a tiny fraction of the mass of hydrogen is lost.
when a smaller star sheds its outer layers, those layers form a colorful cloud, what is it called?
a planetary nebula
What is nucleosynthesis ?
the creation of new atomic nuclei, the centers of atoms that are made up of protons and neutrons.