Study Notes for Integrated Science
Astronomy Unit
These notes will be going over the 2 themes of the unit:
1. The Big Bang Theory
2. Life Cycles of Stars
Big Bang Theory
In this part of the unit we learned about how we scientifically explain how our universe has
come to be. We discussed from the beginning at singularity to the point at which the first stars
began to form. The Big Bang Theory came about by scientists and observers realizing that our
universe is expanding and cooling. This expansion and the microwave radiation left behind from
its origins is how the theory was formulated and then scientifically observed.
The Big Bang theory of the origin of the universe is based on evidence that all galaxies are
rushing apart from one another.
This evidence came by noticing the red shift of the light from other galaxies. As the galaxies
accelerate away from all points their light is stretched and shifted to the red side of the visible
light spectrum. This is a lot like our Balloon Universe Lab. The microwave background radiation
that was examined by satellites, KOBE and WMAP, also help us to understand the age and
distance of this expansion, as well as the first formation of matter.
As space expanded and matter began to cool, gravitational attraction pulled clumps of matter
together, forming the stars and galaxies, clouds of gas and dust, and planetary systems that we
see today.
By examining the observations of our universe’s expansion, we can run time backwards. The
universe would constantly become smaller and smaller, shrinking to almost zero size in 13.7
billion years of rewinding. That is how we calculate the age of our universe being 13.7 billion
years old.
The videos on the website and the notes in your lab journal will help you with diagrams and
visuals.
The Atom
You must know:
Parts of the atom:
proton (positive charge), neutron (no charge or neutral), electron (negative charge), and the
nucleus (the area where most of the mass is, where the proton and neutron are in the center of
the atom).
You will need to be able to draw and label a diagram of the hydrogen and helium atom.
Hydrogen
Helium
Other concepts to remember:
A star is made of atoms of hydrogen gas. These atoms go through the process fusion. Fusion is
where the atoms under extreme pressure and heat come together to create larger and heavier
atoms. These new atoms are new elements. All elements and different types of atoms come
from fusion in stars and supernova explosions.
Life Cycles of Stars
We have been studying the life cycles of large and medium/small stars. Remember that the
route of a stars life cycle is dependent on the mass of the star. There are common stages in all
star life cycles: nebula, protostar, main sequence, and expansion after the hydrogen is nearly
all fused into helium. There are also very different stages that differ the life cycle of:
large starsred supergiant -> supernova-> black hole or neutron star
from that of medium/small starsred giant -> planetary nebula -> white dwarf
Remember that as the matter in the stars create energy from fusion, they also create the elements we use in order to exist: Iron
carbon, nitrogen, oxygen, and many others. Elements bigger than iron are only created in supernova explosions!
Protostar
Be sure to study your poster notes and quiz to help remember the definitions of each stage!!!!