Topic 5: Unit-3 Flashcards
BIRTH, LIFE AND DEATH OF STARS -- Death (9 cards)
What happens when a low-mass star (like the Sun) dies?
The outer layers are ejected, forming a planetary nebula, while the core shrinks into a white dwarf.
What is a white dwarf?
A white dwarf is the dense core left behind after a low-mass star sheds its outer layers, slowly cooling over time.
What happens when a high-mass star dies?
A high-mass star ends its life in a supernova explosion, which occurs when it runs out of fuel and its core collapses.
What is a supernova?
A supernova is a powerful explosion that occurs when a high-mass star’s core collapses, releasing huge amounts of energy and scattering heavy elements into space.
What is a neutron star?
A neutron star is the extremely dense remnant of a supernova, made almost entirely of neutrons and packed into a small area.
How does a black hole form?
If a supernova’s core is massive enough, its gravity will cause it to collapse into a black hole, a region of space where gravity is so strong that not even light can escape.
What is the defining feature of a black hole?
A black hole has such a strong gravitational pull that not even light can escape it, making it invisible to direct observation.
Why are supernovas important for the universe?
Supernovas scatter heavy elements like carbon, iron, and gold into space, enriching future generations of stars and planets.
Summarize the life cycle of a star.
A star is born from a nebula, lives as a main sequence star, and then dies, becoming a white dwarf, neutron star, or black hole depending on its mass.
