The Universe

Google Sky!

Drawing Constellations

The universe is all the matter, ________, and space everywhere.

Size of the Universe

Hubble Telescope Images


Why Do Stars Shine?

A star is a large ball of _________ held together by gravity.The gravity is pulling the gasses together, and this forces a ________ reaction to occur.

Nuclear ___________

H + H = He + ________ and heat

the missing mass is turned into energy



What information can star light tell us?

A. Compostion

Spectroscopes- telescopes with a ___________ inside that break down star light into patterns of colors.

Three Types of Spectra

  1. Bright Line- a few thin bands of ________ against a ________ background. One single element is emitting light and each element has its own unique pattern.
  2. Continuous spectra- a ___________ of smeared colors. Many elements are glowing so bright lines are ___________ together.
  3. Absorption spectra- a rainbow of colors with a few __________ lines. Gas surrounding a star ABSORBS specific colors of light indicating the elements present.

Spectra Lab-

B. Temperature

Blackbody furnance experiments in making steel showed as the furnace heated up its walls glowed different temperatures depending on the heat.

    Electromagnetic Spectrum

    • Hot temperatures emit ________ colors at 25,000 degrees.
    • "Cool" temperatures are ______ in color at 3,000 degrees.

The hotter the temperature, the shorter the wavelength. Therefore, we can tell the temperature of a star just by observing its _________!

  • The order of star temperatures from cool to hot: red-orange-yellow-white-blue

C. Distance, Mass and Brightness

A light year is ____ trillion miles which is the distance that light can travel in a _______.

  • Distances between stars are so great that we need to resort to light years to discuss them.
  • The closest star is Proxima Centauri, 4.2 light years away.

A way we can estimate the distance of a star is by using parallax- the closer a star is to us, the greater the background stars will appear to __________ as we orbit the sun.

Apparent Magnitude- how bright a star appears in the sky. But closer dimmer star may appear ___________.

Absolute Magnitude- how bright the star WOULD appear if they were all the same _________.

  • Measured at 32.6 light years away.

The luminosity (____________) of a star is roughtly dependent on the stars ______. The brighter stars are larger.


Hertzsprung-Russell H-R Diagram

Stars were graphed based on their temperature and absolute magnitude. Something very odd was discovered.

  • _________% of the stars are on the main sequence.
  • 80% of the main sequence stars are ______ dwarfs.

H-R Diagram Lab


Stellar Evolution

Stars evolve too!

Small Mass Stars

When our sun runs out of hydrogen it will turn into a ________ Giant and expand all the way into the orbit of Mars swallowing the _______. Some day your atoms will be part of the SUN! How much time do we have left? _____ billion years!


Large Mass Stars

  • Nebula- Protostar- Main Sequence- Red Super Giant- Super Nova- Black Hole OR Neutron Star
    • The constellation ORION has a super red giant and a blue giant!

    Black holes- so dense they capture their own light.

    • Black holes are invisible but we can see their ____________ effect on surrounding stars.
    • Also gas from surrounding stars can be observed being _________ into the black hole. As it spirals inward it heats up and emits large amounts of X-ray radiation.

Einstein (1879-1955)

      • The _________ you move, the slower time passes. Twin paradox!
      • General Theory of Relativity- space-time and light are curved by ____________. Matter deflects light itself!!!! One test of this theory was provided during a solar eclipse. Stars behind the sun were visible!!! This explains why a black hole captures its own light!

Tour of the invisible.

Gravitational Waves

Gamma Ray Bursts Explained

How Old is the Universe?

The universe formed 13-14 ________ years ago.

The universe began with the "Big _______."

  • A hot tiny sphere of _________ exploded in an incredible burst and began moving outwards.
  • The first 700,000 years were _______- energy had to cool down enough to convert into matter.
  • The universe is still __________ outwards

Calender game


How do we know that the universe is expanding? (Proof of the big bang)

  1. Background Radiation: The remaining __________ of the Big bang is faint and cool and found EVERYWHERE in the sky.
  2. Red Shift: Light from the _________ around us appears to stretch and turn red as they race away from us.
    • Red light has a ________ wavelength then blue light. Because all the stars are moving away from us (except those in our Milky Way galaxy) their light appears to have lengthened into longer wavelengths and turned ______.
    • Blue visible light has a much ________ wavelength than red visible light. If an object is moving toward you, the electromagnetic energy that the object gives off will crowd together. This is called the Blue shift, because the wavelength __________.




  • We can determine how fast a galaxy is moving toward or away from earth by analyzing the degree of red or blue shift.
    • All galaxies are moving away from us, except for the Andromeda galaxy which exhibits a __________ shift.
  • Hubble's Law- the farther a galaxy is away from us, the __________ it is moving, the greater the red shift.
    • The universe is expanding and its speeding up at a faster rate!!! Space is being added between matter.

Power of 10- Travel off the Earth's surface 10 times more each 10 seconds!

What is most of space filled with? ____________


Four Types of Galaxies

Hubble Image of Galaxies

1. Spiral- 30% of the galaxies

  • older stars are in the __________ and younger stars are on the arms
  • A barred-spiral galaxy is a common type of spiral galaxy

2. Elliptical- 60% of the galaxies

  • mostly older stars

3. Irregular- 10% of the galaxies

  • mostly blue giants

What galaxy are we in?

The __________ Way, a spiral galaxy.

  • It contains 200 -400 billion stars
  • It measures 100,000 by 30,000 light years.
  • The center of our galaxy is a _________ hole

Galaxy Song and Lyrics

Galaxy Lab-

Local Group

  • Like stars, galaxies evolve and group themselves into clusters.
  • Our Milky Way and other near by galaxies form a Local Group of 35 galaxies.

Deep Space

  • Within a sector of the sky, about the size of a grain of rice, high resolution photos taken for several WEEKS by the hubble telescope reveal ______________ of galaxies.


Cosmic Survey

What are your ideas about the universe?

The Composition of the Universe:

The Search for Dark Energy and Dark Matter

Extra Credit: Video Questions

4% Ordinary Matter- The _____ matter that makes up you and me

26% Dark Matter- __________ matter that doesn't interact with light. We know its there because of it's ____________ effect on ordinary matter. It pulls things together.

70% Dark Energy- Invisible energy that causes the universe to ____________. It pushes things apart.