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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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