Learning Target Inventory Class: Integrated Earth/Space Science Unit 1: The Universe and Its Stars
HS-ESS1-1 LT4 I can create a model based on evidence to illustrate the lifespan
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of the sun (H-R diagram) and interpret observations of the masses and lifetimes of
other stars. Honors; page 681-692, CP; page 844-851
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The birthplaces of stars are dark, cool interstellar clouds, which are rich in dust and gases.
Mutual gravitational attraction of the particles causes the cloud to contract, pulling every
particle toward the center. As the cloud shrinks, gravitational energy is converted into
heat energy and the mass of contracting gases slowly heats up.
A protostar starts to form when the interstellar cloud reaches a temperature high enough
to cause it to radiate energy of red light making it appear to be a large red object that
doesn’t engage in nuclear fusion.
The star becomes a stable main-sequence star when the increased atomic fusion
produces hydrostatic equilibrium. Our sun is a main-sequence star.
When the usable hydrogen in the star’s interior is consumed, the red giant stage begins.
The core begins to contract. The additional energy from this compression initiates a more
vigorous level of hydrogen fusion in the star’s outer shell and enormously expands the
star’s outer gaseous shell. Eventually the star enters a cooler, stable state, only larger.
Once fuel is exhausted in the red-giant stage, the star collapses into an Earth-size body of
great density called a white dwarf. It has a high surface temperature. There is no more
nuclear energy.
The white dwarf cast off its bloated outer atmosphere creating a cloud of gas which is
heated by what energy is left in the white dwarf causing the gases to glow. These
gleaming spherical clouds are called planetary nebulae.
About 90% of all stars fall along a band that runs from the upper-left corner to the lower
right corner of the H-R Diagram.
The main-sequence stars appear in decreasing order, from hotter, more massive blue stars
to cooler, less massive red stars.
Red giants are above and to the right of the main sequence in the H-R Diagram. They are
very luminous stars.
In the lower-left portion of the H-R Diagram, the white-dwarfs are much fainter than
main-sequence stars and smaller.
Rating scale: 1=I have no idea
Muddiest Point:
Thinking Stem log:
Guided Reciprocal Peer Questioning
3= making progress; partially okay
5=mastery! 
Learning Target Inventory Class: Integrated Earth/Space Science Unit 1: The Universe and Its Stars
2 minute reflection
3-2-1
Three things that I will
remember:
Two things that I am most
struggling with:
One thing that will help me
for tomorrow:
POMS - Point of Most Significance:
I used to think…but now I know…
Look Back – What have you learned and how have you learned it?
What I learned:
How I learned it:
Learning Target Inventory Class: Integrated Earth/Space Science Unit 1: The Universe and Its Stars