Week 8
Stars
Last week we learned about the origins and construction of The Universe. This week we will learn more about its structure and how it works as a whole.
Day 1
Space Probe Project Team Meetings.
Turn in project proposal in a Google Doc.
Once awarded your location, begin research and Google Slide development (always a good idea to split up the work).
Day 2
Part 3
The-Story-Of-Everything-By-Stephen-Hawking-Part-3[www.savevid.com].mp4Molecular Motion - As molecules move faster and heat up when compressed. Gravity compresses hydrogen gas clouds generated by the Big Bang to produce stars.
Nuclear Fusion combines smaller nucleus atoms into larger ones and in the case of Hydrogen produces massive amounts of energy in the process.
E= MC2 simply means that energy is equal to matter and matter is equal to energy.
The first stars were huge blue stars that had short lives and ended in a supernova explosion that splashed all of the elements in the periodic table across light years of space.
Supermassive Black Holes are at the center of galaxies and help hold them together.
Star layer density - Hydrogen is less dense than Helium and the inside of a star layers just like the inside of the Earth; by density.
Part 4
The-Story-Of-Everything-By-Stephen-Hawking-Part-4[www.savevid.com].mp4Go to 7:51 on day 1.
Our galaxy, the Milky Way, has approximately 200,000,000 stars and has a supermassive black hole in the center that has the mass of 4 million Suns. It is the hub around which galaxies form and take shape.
Black holes smaller than about 4 solar masses evaporate by emitting Hawking Radiation.
Nebulas are any large cloud of gas and dust from which stars can be born. Supernova explosions can create remnants called nebulas.
Day 3
Stars, planets, and galaxies form much the same way. Gravity pulls in matter. The spiraling is due to every particle having an initial velocity and the totaled average of force and motion (see video)
A star is formed when Hydrogen fusion begins. The energy of fusion sweeps out lighter particles and gases from the inner solar system (solar wind). This is why the inner planets are rocky and the outer planets are gassy.
Gravity pulls matter towards the core and the energy of fusion creates pressure that pushes against gravity. Gravity and pressure are equal during the main sequence and then fluctuate during the giant phase.
In the giant phase of a star's life Iron fusion does not produce energy and the star begins to contract. Unburned fuels begin to ignite with increased temperature and pressure. The star expands to many times its original size until it again fuses as much fuel as it can at that temperature. In the final moments of a star it falls quickly toward the core creating temperatures of 1 billion degrees. The falling material simultaneously bounces off of the core and fuses any remaining elements in a violent supernova.
More about star life cycles here.
Star LIfe Cycles - stars are formed in nebulas which are mostly hydrogen gas (the most abundant element in the Universe). Gravity pulls the gas together. The friction and pressure at the center cause nuclear fusion of Hydrogen. Hydrogen to Helium fusion marks the main sequence of a star's life cycle. The giant phase begins when Helium fusion starts.
Massive stars live short lives and end as a neutron star or black hole. Less massive stars have longer lives and end as a white dwarf.
Star Life Cycles
Day 4
Space Probe Project Team Meetings
Day 5
Stars Study Guide
Know what elements are being produced in stars and when.
What causes stars to go supernova?
What did the first stars in the Universe most likely look like?
What causes stars to contain layers of elements inside?
Know the relationship between molecular motion and temperature.
Know the relative temperature of different color stars.
Predict what will happen to stars of different masses during their life cycle.
Know the structure of, solar systems, galaxies, and stars.
Know what stars are made of, where they form, and what they produce when they die.
All late work is due upon arrival in class.
Review
Quiz in Google Classroom
Work on Space Probe Project