The color of the hottest stars.
What is "blue"?
What is "a nebula"?
The element stars are mostly composed of when they first form.
What is "hydrogen"?
This is the *final* outcome for the highest mass stars.
What is "a black hole?"
This is the name for the low mass star once it has started to fuse helium into heavier elements.
What is "a red giant?"
The approximate location of our Sun on the H-R diagram.
What is "close to the middle?"
This exerts such a strong gravitational pull that no light escapes.
What is "a black hole"?
The element that hydrogen next fuses into.
What is "helium?"
The phase that high mass stars enter after they begin fusing helium/He.
What is "a red supergiant"?
This happens to the outer layers of a star as the core contracts and heats up.
What is "expands?" (synonyms are acceptable here)
The name of the hottest, smallest stars on the H-R diagram.
What are "blue dwarfs?"
The name for the phase in a life cycle just before fusion starts.
What is "a proto-star"?
This element represents the point in the periodic table at which fusion begins absorbing energy instead of releasing energy.
What is "iron/Fe"?
The element that the highest mass stars can fuse in their core before becoming a supernova.
What is "iron/Fe"?
The two forces that are constantly interacting throughout a star's life cycle.
What are "gravity" and "fusion?"
The name of the stars in the highest, right-hand region of the H-R diagram, being specific.
What are "red supergiants?"
An immense explosion that occurs when a red supergiant begins to fuse iron.
What is "a supernova"?
The type of elements that can only be fused in a supernova.
What are "elements heavier than iron?"
A red supergiant, which is visible from Earth and located in the constellation Orion.
What is "Betelgeuse"?
This layer of the mid-sized star stays intact throughout its life cycle.
What is the "core?"
The coolest, smallest type of star on the H-R diagram.
What are "red dwarfs"? (What are brown dwarfs? will also be accepted)
The stage between a red giant and white dwarf.
What is "a planetary nebula?"
The type of fusion that leads to a neutron star (thinking about what fuses into a neutron).
What is "the fusion of electrons and protons"?
This is a phase that some massive red supergiants go through when they contract for a period of time, before becoming a red supergiant again.
What is "a blue supergiant?"
This is approximately how long a star the size of our sun will remain in the main sequence.
What is "10 billion years?"