Star Birth & Formation
Where are stars born?
In nebulas (clouds of gas and dust).
What single factor determines a star's temperature, lifespan, and path?
Its mass.
What element do helium atoms fuse into when hydrogen runs out?
Carbon.
What type of giant star does a massive star become after the main sequence?
A red supergiant.
What dense object forms if a supernova core is under 4 solar masses?
A neutron star.
What force pulls gas and dust together to form a star?
Gravity.
What fuel do main sequence stars burn in their cores?
Hydrogen (fusing into helium).
What happens to a Sun-like star's outer layers when it becomes a red giant?
They expand and cool down.
What is the heaviest element produced by normal star core fusion?
Iron.
What subatomic particles make up a neutron star?
Neutrons.
What two conditions must increase inside the core before a star ignites?
Temperature and pressure (or density).
What two main properties are plotted on an HR Diagram?
Luminosity (brightness) and temperature (or spectral class).
What causes a star to collapse inward when fusion stops?
Gravity takes over.
Why can't stars fuse elements heavier than iron during normal life?
Fusing iron consumes more energy than it creates.
What forms if a remaining supernova core is over 5 solar masses?
A black hole.
What process officially starts a star's life?
Nuclear fusion.
What outward force balances gravity to keep a main sequence star stable?
Nuclear fusion pressure.
What glowing, Earth-sized leftover remains after a red giant dies?
A white dwarf.
What violent explosion occurs when a massive star collapses?
A supernova.
Why can light not escape a black hole?
Its gravity is too strong.
What famous star-forming nebula is named in the text?
The Orion Nebula.
Why do high-mass stars die much faster than low-mass stars?
They burn through their fuel much faster.
What is the total main-sequence lifespan of our Sun?
About 10 billion years.
How are elements heavier than iron (like gold and uranium) created?
In the extreme energy of a supernova explosion.
How do astronomers spot black holes if they don't emit light?
By their gravitational effects on nearby objects and surrounding radiation.