starter: post test practice: notes ; glue here when done 2/27/2015 193 194 2/27/2015...
TRANSCRIPT
Starter: Post Test
Practice: Notes ; glue here when done
2/27/2015
193 1942/27/2015
Connection/Exit: Write a 5 sentence summary of your notes.
Galaxies Notes and Activity
Application:
Galaxies Notes and Activity
Number
Type of Galaxy
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10
February 27, 2015AGENDA
Objective 8.8ADescribe components
of the universe, including stars,
nebulae, and galaxies, and use models such as the Herztsprung-Russell diagram for
classification by reading and writing
while taking notes and identifying activity.
1. Starter2. Notes 3. Activity4. Exit
Date Lecture/ Activity/ Lab Page
Table of Contents
2/20 Formation of the Universe 185-1862/23 Big Bang Lab 187-1882/24 Lives of Stars 189-1902/25 Characteristics of Stars 191-1922/27 Galaxies 193-194
Galaxies
A galaxy is a collection of stars, gas and dust held together by gravity.
Scientists estimate that there are more than 100 billion galaxies scattered throughout the visible universe.
Galaxies range from 10,000 to 200,000 light-years in size.
Galaxies
Contents of a Galaxy
Globular clusters-groups of older stars
Contents of a Galaxy
Gravity holds the billions of stars together, and the densest region is in the center, called a core or bulge.
All galaxies have a faint outer region or envelope and a mysterious dark matter halo.
Contents of a Galaxy
Quasars- star-like sources of light; may be cores of young galaxies
Contents of a Galaxy
Nebulas- large clouds of dust and gas; birth place of stars
Types of Galaxies
Altogether, a galaxy contains billions of stars and there are trillions of galaxies distributed across the Universe.
There are four main types, spiral, barred spiral, elliptical and irregular.
Spiral Galaxies
Have a bulge in the middle and spiral arms
the center of a spiral is made of old stars,
arms made with young stars that formed recently out of gas and dust.
shape caused by the rotation of the galaxy
We live in the Milky Way, a Spiral Galaxy.
Barred Spiral Galaxies
Barred spirals have a round or oval bulge with a nearly rectangular bar across it.
The spiral arms attach to the bar rather than the bulge.
Two thirds of all spiral galaxies are barred spirals and after a certain amount of time, the bars disappear.
Have no star formation or any visible features.
Most have thousands of globular clusters
Contain mostly old stars Have bright centers and
very little dust and gas Looks like a sphere
Elliptical
Elliptical galaxies might be formed when two galaxies merge
Mostly have grainy, highly irregular groups of bright areas.
They have no noticeable symmetry nor obvious central core
Made of younger stars They don’t fit any other
class Found near spiral
galaxies▪ Ex. Magellanic
Clouds
Irregular
Appplication/Connection: Identifying Galaxies
The next 10 slides are different pictures of galaxies.
As we go through the pictures, in the chart in your journal, write down the name of
which type of galaxy you think each picture is.
Try to get as many as you can correct.
We will review in the end.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
1.
Irregular
2.
Barred Spiral
3.
Irregular
4.
Elliptical
5.
Spiral
6.
Irregular
7.
Spiral
8.
Elliptical
9.
Elliptical
10.
Barred Spiral
Starter: Post Test
Practice: Notes ; glue here when done
2/27/2015
193 1942/27/2015
Connection/Exit: Write a 5 sentence summary of your notes.
Galaxies Notes and Activity
Application:
Galaxies Notes and Activity
Number
Type of Galaxy
1
2
3
4
5
6
7
8
9
10