Star Life Cycles
This is the process where hydrogen atoms fuse to form helium in a star's core.
What is nuclear fusion?
The main sequence on the H-R diagram represents stars in this stage of their life cycle.
What is hydrogen fusion in their cores?
The event that sets off a supernova explosion in a massive star is the fusion of this element.
What is iron?
The term astronomers use to describe gas and dust between stars.
What is the interstellar medium?
This formula describes how mass can be converted into energy.
What is E=mc2?
A star with a mass like the Sun will end its life as this type of stellar remnant.
What is a white dwarf or what is a planetary nebula?
Stars that spend the longest time on the main sequence are of this spectral type.
What is M-type?
These cool, dark regions on the Sun's surface are associated with strong magnetic fields.
What are sunspots?
This type of cloud is where stars are most likely to form.
What are giant molecular clouds?
The Sun has been fusing hydrogen for approximately this length of time.
What is 4.5 billion years?
Massive stars use this process to power themselves.
What is the CNO cycle?
A star in the upper right quadrant of the H-R diagram has these two general properties.
What are low temperature and high luminosity?
A neutron star emits rapid pulses of radiation and is called this.
What is a pulsar?
The pink color often observed in nebulae comes from this element.
What is hydrogen?
This stage marks the "birth" of a star.
What is the beginning of nuclear fusion?
When a massive star explodes as a supernova, its core may become this dense object.
What is a neutron star?
This property of stars is plotted along the vertical axis of the H-R diagram.
What is luminosity?
This type of supernova event leaves behind a core.
What is a type II supernova?
This nebula, named after a hunter, is a large cloud of gas and dust illuminated by newly formed stars.
What is the Orion Nebula?
This property determines whether a star will ultimately become a black hole.
What is its mass?
The temperature and density of this star type are too low for it to sustain hydrogen fusion.
What is a brown dwarf?
The H-R diagram turn-off point provides clues about this important characteristic of a star cluster.
What is its age?
A white dwarf becomes a Type Ia supernova when it exceeds this limit.
What is the Chandrasekhar limit?
This type of nebula is difficult to observe because it blocks visible light from passing through.
What are dark nebulae?
These dense clusters of stars contain some of the oldest stars in the galaxy.
What are globular clusters?