1. The Big Bang, Galaxies, & Stars
Astronomy
The study of the Universe, stars, planets, and all other objects in space.
The Big Bang, Galaxies, & Stars

2. The Universe Composed of empty space, energy, and matter.
Matter = gasses and dust particles
When matter comes together, stars, planets, meteors, asteroids, and comets form.

3. The Visible Universe
The Hubble telescopes allows astronomers to gaze into deep space.
New galaxies are discovered

4. How did the universe begin???
Big Bang Theory marks the origin of the universe
Occurred about 13.7 billion years ago
All matter and space was created
Not a huge explosion that hurled matter in all directions. Technically, there was no “bang”

5. 4 Stages of the Big bang Theory
All matter and energy in the universe was once located in a single dense point called a singularity.
A rapid expansion occurred.
Matter and energy were propelled outward in all directions as the universe began to expand.
Matter began to condense - forming galaxies and these galaxies continue to expand today.

6. Raisin bread analogy of an expanding universe
Raisins represent stars and galaxies.
According to the Big Bang Theory, all stars and galaxies are moving away from each other.

8. Life Cycle of Stars 1st Step: Stars form from nebulas
Regions of concentrated dust and gas
Gas and dust begin to collide, contract and heat up
All due to gravity

9. Life Cycle of Stars 2nd Step:
As nebula contracts, a small star is formed
Called a protostar
Eventually, the protostar will begin nuclear fusion
Hydrogen protons attract to each other
Strong nuclear force
Fusion begins
Necessary for stars to survive

10. Life Cycle of Stars 3rd Step: Star joins the main sequence
90% of stars spend life here
Nuclear fusion = Hydrogen into Helium
Mass of star determines location on main sequence

11. Life Cycle of Stars Beginning of the End:
Stars begin to die when they run out of hydrogen
Gravity begins to take over
Star core begins to shrink; outer core of hydrogen begins to fuse
Star gets bigger

12. Life Cycle of Stars Beginning of the End:
When star gets bigger, it cools down
Red giant
Eventually, star can fuse helium into other elements
Carbon, oxygen, and other heavier elements

13. Life Cycle of Stars Beginning of the End:
Once star runs out of “fuel”, star shrinks under its own gravity
Turn into a white dwarf, neutron star, or black hole

14. Life Cycle of Stars Death of Stars:
What stars end up as depend on mass
Low and Medium mass stars
Planetary nebula white dwarf
High mass stars
Supernova neutron star or black hole

15. Life Cycle of Stars Death of Stars: Low and Medium Mass
Main Sequence Star
Red Giant
Planetary Nebula
White Dwarf

16. Life Cycle of Stars Death of Stars: High Mass Main Sequence Star
Red Super Giant
Supernova
Neutron Star
Black Hole

17. Black Holes What is a Black Hole??? Black Holes Info Sheet
An object so massive and dense that not even light can escape its gravity
The end result from a supernova of a star that has a mass greater than 3x the sun

19. Life Cycle of Stars High Mass Stars: Mass greater than 8x our sun
Create high mass elements such as iron
Neutron Star
Formed if remaining star < 3x sun’s mass
Black Holes
Formed if remaining star > 3x sun’s mass

20. Life Cycle of the Sun
As fusion begins to slow down, the core of the sun will contract
Temperature in the core will rise
The outer layers of the sun will expand, consuming in the inner planets
Sun will become a Red Giant

21. Life Cycle of the Sun

22. Life Cycle of the Sun
Core of the sun will begin to fuse helium into larger elements such as carbon and oxygen
Continuing over the next 100 million years…
Core will become entirely carbon and oxygen
Core will contract
Outer layers will expand
Outer layers will form a planetary nebula
Core of sun will become a white dwarf

23. The Hertzsprung-Russell Diagram
An H-R diagram plots stars according to their luminosity and temperature (or spectral class)
5/23/2019

24. Do Now Describe the big bang theory in your own words
Explain why we experience 4 different seasons every year.

25. EARTH'S ROTATION AND REVOLUTION

26. Earth’s Rotation Rotation is the spinning of the Earth on its axis.
The time for one rotation is 24 hours.
The speed of rotation 24,855 miles/24 hr or 1,038 miles/hr

27. Earth’s Rotation – Causes daily changes
The spinning of earth on its AXIS
the imaginary line through the planet from the North Pole to the South Pole – is its rotation
The axis of the earth is tilted 23.5°
Earth’s rotation
West to East
How many degrees is a circle? _____
How many hours in one day? _____
SO, how quickly does the Earth rotate?
15 degrees / hour

28. Effects of Rotation
Star Trails
Arc of the Sun in the sky
Day/Night

29. How do we know the Earth is really turning?
Foucault Pendulum
A pendulum was set moving and will continue to swing unless an outside force was acted upon it

30. No force that makes pendulum rotate – must be earth that is rotating!!!
Inertia and gravity make it swing straight out and straight down in a straight arc – not twist.

31. How do we know the Earth is really turning?
Coriolis Effect – the tendency of objects moving over the earth (air, water, planes, projectiles) to be deflected (curve away) from a straight line path.

32. Earth’s Revolution
A revolution occurs as the earth moves around the sun.
Time for one revolution = 365 1/4 days = 8,766 hours
The speed of earth’s revolution is about 18 miles per second.

33. Earth’s Revolution

34. Earth’s Orbit
The path an object takes as it revolves around another object.

35. Around and Around We Go
Every second, that you sit in this classroom, the Earth's orbital motion carries you about 18 miles through space.

36. Evidence of Earth’s Revolution around the Sun
Seasonal Constellations: Because of the Sun’s annual motion, some constellations are visible at night only during certain seasons.
Constellations are visible when the dark side of Earth (away from sun) faces toward the constellation.

37. The 13 constellations the sun appears to travel through during the year

38. Apparent Motion of Sun due to Rotation and Revolution
Rotation: Sun – apparent daily path from sunrise to sunset has the shape of an arc moving l5° per hour.
Revolution: However, the sun’s arc changes both its position and its length with the seasons

39. Summer maximum altitude of noon sun is 73°, Winter is 26° Spring/Autumn?
(Sun 90 at = =72.5) ( 90-41= 49) ( = = 25.5)