Download T3-W10-0501student

Bell Work:
1. What do all stars begin
their life as ?
Physical Science 5/1
Agenda:
Lives of Stars
HertzSprung Russell WS
Outer Space WS
Learning Target:
2. What kind of star will this
form?
I can descrbe the life cycle of a star.
I can explain how stars differ in size,
temperature , and color.
Homework/Important Dates:
What does “proto” mean?
○ 15.3 + 15.4 Book Notes,
Vocab. And Outer Space WS
due Thursday 5/4
○ Unit 6 Test on Tuesday 5/16
Physical
Science
Notes
Lives of Stars
The Life of Stars
 Stars


start their lives as parts of nebulas.
Nebulas are large clouds of gas and dust spread out
over a massive area.
In the densest part of nebula, gravity pulls the gas and
dust so closely together that nuclear fusion starts.
 The
next stage is a protostar, which is the earliest
stage of the star’s life.
The Life of Stars
 The

mass of the star determine its lifespan.
The smaller the star, the longer the life.
 The
size of the star also determines what path it will
take as it goes through its cycle.

High mass protostars take a different path than lower
mass protostars.
The Life of Stars
 The
next stage in the life of a star is the main
sequence.


This is the stage our sun is in.
Higher mass stars tend to burn hotter.
 Low
mass stars expand into red giants, while high
mass stars expand into supergiants.

These are low temperature stars that burn slowly
because they have used all their hydrogen.
The Life of Stars
 If
it is a low mass star, the next stage after the red
giant is the planetary nebula.

A
The star expands and the parts drift apart, forming a
nebula.
high mass star will go supernova, suddenly
exploding and releasing massive amounts of
energy.
The Life of Stars
 Low
mass stars leave their cores behind when they
turn into planetary nebulas.



The core cools and compresses and turns into a white
dwarf.
White dwarfs have about the same mass as the sun,
but they have the size of Earth.
Nuclear fusion no longer takes place, but the star
continues to shine with leftover energy.
The Life of Stars
 High
mass stars have two paths.
 Neutron stars are the left over cores of the
supergiant.


They are much like white dwarfs, but a million times
denser.
Spinning neutron stars are called pulsars.
 Pulsars
emit radiation in predictable patterns.
The Life of Stars
 The



other path is a black hole.
Only the densest stars become black holes.
Nothing can escape the gravity of a black hole, not
even light.
Scientists can only detect black holes based on how
they affect other stellar bodies.
Hertzsprung-Russell Diagrams
 The
HertzsprungRussell diagram
(HR diagram) is a Bright
way for scientists
to classify stars
and understand
how they change
over time.


The x-axis
represents
temperature. Dim
The y-axis
represents
absolute
brightness.
Hot
Cold
Hertzsprung-Russell Diagrams
 More
than 90% of
stars are in the
main sequence.

Stars in the main
sequence have
their brightness
increase in
proportion to
their
temperature.
 Stars
that have
started to die
tend to stray off
the main
sequence.

These stars have used up all the
hydrogen and started to expand,
or are white dwarfs that have
already passed through that
phase.
Hertzsprung-Russell Diagrams
 Why
are the
giants so bright,
even though they
are not so hot?
 The brightness of
a star is based on
both its
temperature and
how big it is
 Giants
are much bigger than main sequence stars,
so they have a much larger surface area to emit
light.
Bell Work:
1. Describe all the stages of a
high-mass star’s life.
Physical Science 5/2
Agenda:
Bill Nye - Space Exploration
Spectroscopes
Life Cycle of a Star / Absorption
Spectrum WS
HR Diagram
Learning Target:
I can describe the life cycle of a star.
I can explain how stars differ in size,
temperature , and color.
Homework/Important Dates:
○ 15.3 + 15.4 Book Notes,
Vocab. And Outer Space WS
due Thursday 5/4
○ Unit 6 Test on Tuesday 5/16
○ H-R Diagram WS due =
Friday
○ Life Cycle of a Star WS =
Friday
Using a Spectrograph



Point the slit end of the spectrograph towards the
light source.
Look through the other end for the spectra that
will appear to side of the slit.
Compare and contrast the different light sources.
Light source
Description of Spectra
Example observations to look for:
Do the colors blend/fade from one to the next or are they
separate bands?
Which color is dominant?
Are any colors missing/separated?
Complete Absorption Spectrum WS on the back of Life
cycle of a star.
Bell Work:
1. Describe all the stages of a lowmass star’s life.
Physical Science 5/3
Agenda:
Cosmos: A Spacetime Odyssey
Learning Target:
Homework/Important Dates:
○ 15.3 + 15.4 Book Notes,
Vocab. And Outer Space WS
due Thursday 5/4
○ Unit 6 Test on Tuesday 5/16
○ H-R Diagram WS due =
Friday
○ Life Cycle of a Star WS =
Friday
Bell Work:
○What is a planetary
nebula?
Physical Science 5/4
Agenda:
Review Quiz
Review Outer Space WS
Learning Target:
○What is a white dwarf?
I can descrbe the life cycle of a star.
I can explain how stars differ in size,
temperature , and color.
○What are neutron stars?
Homework/Important Dates:
○What are black holes?
○ Unit 6 Test on Tuesday 5/16
Bell Work:
○Diagram the life of either
a low or high mass star.
Physical Science 5/15
Agenda:
Quiz
Unit Test Study Guide
Friday Weekly
Assignments:
1. Bell Work
2. Notes
3. Book Notes
4. Hertzsprung Russell
5. Outer Space WS
6. Life Cycle of a star WS
Homework/Important Dates:
Unit 6 Test on Tuesday 5/16