Transcript Star Life Cycles.ppsx

Topic: The Life
Cycle of Stars
PSSA: 3.4.7.D/S8.D.3.1
Objective:
• TLW identify the major events
in the life cycle of main
sequence and massive stars.
MI #1: Nebulae
• Nebulae (or nebulas) are large
clouds of dust and gas in space.
• Hydrogen in the nebula is
converted to helium through
nuclear fusion eventually
generating a star.
MI #2: Main Sequence Stars
• This is the longest part of a star’s
life cycle.
• Eventually main sequence stars
use most of their hydrogen and
begin to cool.
MI #3: Main Sequence Stars
(Part 2)
• Giants and supergiants form when
main sequence stars expand after
cooling.
• When a giant star finally collapses, it
forms a white dwarf.
• White dwarf stars burn hot, but do
not generate additional energy
through fusion.
MI #4: Supernovas
• A supernova is a giant explosion of a
massive star that occurs when it collapses
and throws its outer layers into space.
MI #5: Neutron Stars
• Neutron stars are the collapsed
core of a supernova.
• There is so much gravity that the
electrons and protons are
smashed together to form
neutrons.
• If the neutron star is spinning it is
called a pulsar.
MI #6: Black Holes
• Black holes form if the mass of the center
of a collapsed star is more than three
times the mass of the sun.
• Black holes are so massive that their
gravity prevents light from escaping.
So What…? Real Life Application
• Understanding the life cycle of a
star helps us understand why
there are different types of stars,
as well as why supernovas and
black holes form.