starsGalaxies.ppt

7/28/2019 starsGalaxies.ppt

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Stars and Galaxies

Space Science for Middle School at HCDE

February 20, 2009

Created by the

Lunar and Planetary InstituteFor Educational Use Only

LPI is not responsible for the ways

in which this powerpoint may be used or altered.

Image at http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2009/07/image/g/results/50/
http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2009/07/image/g/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2009/07/image/g/results/50/


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Welcome!

Please complete the pre-assessment

Its for usits not about you

Please let us know how much YOU know,

not how much your friends sitting next to

you know


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What are we going to cover?

Our Place in the Universe

The Electromagnetic Spectrum

Classifying Stars

Classifying Galaxies

History of the Universe


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First up


What is our Universe made of?

How big are things? How far away?

How do we know?


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What is our Universe made of?

Stars and planets

Gas and dust

Organized into star clusters

Organized into nebulae

Organized into galaxies

Other things:

Black holes

Dark matter

Dark energy

What was in your drawing?

Image fromhttp://galileo.rice.edu/lib/student_work/astronomy95/orionpleiades.html
http://galileo.rice.edu/lib/student_work/astronomy95/orionpleiades.htmlhttp://galileo.rice.edu/lib/student_work/astronomy95/orionpleiades.htmlhttp://galileo.rice.edu/lib/student_work/astronomy95/astrogrobs/pleiadesbig.gif


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Activity!!

Use the Venn diagrams to place the

stickerswhere does everything go?

After youre finished, lets discuss


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Examining the Components

Stars

Gas and dust (Nebulae)

Star clusters

Galaxies


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Different

types of

stars

Image from

http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2003/21/image/a/results/50/
http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2003/21/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2003/21/image/a/results/50/


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Types of Stars

Big

Small

Red

Blue

YellowIn groups

Alone

More later


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What is a star cluster?

stars formed together at

same time

stars may be

gravitationally bound

together

two types: open(galactic) and globular

Image athttp://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2007/18/image/a/format/web/results/50/
http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2007/18/image/a/format/web/results/50/http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2007/18/image/a/format/web/results/50/


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Open Clusters

dozens to thousands of stars

young stars! only a few

million years old

may still be surrounded by

nebula from which they formed

located in the spiral arms of agalaxy

example: Pleiades

Image at http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2004/20/image/a/results/50/
http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2004/20/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2004/20/image/a/results/50/


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More open star clusters

Image from http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2006/17/image/a/results/50/
http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2006/17/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2006/17/image/a/results/50/


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Globular Clusters

millions to hundreds of millions of

stars

old! 6 to 13 billion yearsmostly red giants and dwarfs

stars are clumped closely together,

especially near the center of the

cluster (densely) surround our disk as a halo

Image at

http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/1999/26/image/a/results/50/
http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/1999/26/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/1999/26/image/a/results/50/


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What is a nebula?

A cloud in spaceMade of gas and dust

Can have stars inside

Most of the ones we see are inside our Milky

Way Galaxy

Different types

Orion image at http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/
http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/


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Large, massive, bright nebulae

Emission Nebula

The hot gas is emitting light



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Colder, darker nebulae

Dark dust blocking the hot

gas behind it

NOAO/AURA/NSF Image fromhttp://hubblesite.org/newscenter/archive/releases/nebula/dark/2001/12/image/c/results/50/
http://hubblesite.org/newscenter/archive/releases/nebula/dark/2001/12/image/c/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/dark/2001/12/image/c/results/50/


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Leftovers from an Explosion

Supernova remnant

(smaller, less gas)

Image at http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/
http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/


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What is a galaxy?

A large group of stars outside of our own Milky Way

Made of billions to trillions of stars

Also may have gas and dust

Spiral, or elliptical, or irregular shapedImage at http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2007/41/results/50/
http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2007/41/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2007/41/results/50/


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Spiral galaxy--Andromeda

NOAO/AURA/NSF Images at http://www.noao.edu/image_gallery/html/im0606.html andhttp://www.noao.edu/image_gallery/html/im0685.html
http://www.noao.edu/image_gallery/html/im0606.htmlhttp://www.noao.edu/image_gallery/html/im0685.htmlhttp://www.noao.edu/image_gallery/html/im0685.htmlhttp://www.noao.edu/image_gallery/html/im0606.html


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Elliptical Galaxies

Images at http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/and http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/
http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/


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Irregular Galaxies

NASA and NOAO/AURA/NSF Images at

http://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/ ,

http://www.noao.edu/image_gallery/html/im0560.html , and http://www.noao.edu/image_gallery/html/im0993.html
http://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/http://www.noao.edu/image_gallery/html/im0560.htmlhttp://www.noao.edu/image_gallery/html/im0993.htmlhttp://www.noao.edu/image_gallery/html/im0993.htmlhttp://www.noao.edu/image_gallery/html/im0560.htmlhttp://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/


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Our Galaxy: the Milky Way

has about 200 billion stars, and lots of gasand dust

is a barred-spiral (we think)about 100,000 light-years wide

our Sun is halfway to the edge, revolving athalf a million miles per hour around thecenter of the Galaxy

takes our Solar System about 200 millionyears to revolve once around our galaxy


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The Milky Way

Image at http://news.nationalgeographic.com/news/bigphotos/1945371.html
http://news.nationalgeographic.com/news/bigphotos/1945371.htmlhttp://news.nationalgeographic.com/news/bigphotos/1945371.html


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Mapping the Milky Way

We can see stars

star clusters

nebulae

Galaxies

Lets try to Map our Galaxy

How do we know what our Galaxy

looks like?


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Measuring Distances

Parallax (lets model it) As Earth orbits the Sun, we see nearby stars move relative to more distant stars

How many degrees did the plate move, relative to the background?

Can you calculate the distance to the plate?

Sine of the parallax (angle) x Earths distance to the Sun = Distance to the star

The angles involved for strellar observations are very small and difficult to

measure. Proxima Centauri, has a parallax of 0.77 arcsec. This angle is

approximately the angle subtended by an object about 2 centimeters in diameter

located about 5.3 kilometers away.


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Measuring Distances

What is a Light Year? A light year is the distance light travels in a year. Light moves at a

velocity of about 300,000 kilometers (km) each second; how far

would it move in a year?

About 10 trillion km (or about 6 trillion miles).

Why do we use light years? Show me how far 5 centimeters is.

Now show me 50 centimeters.

Now tell me (without thinking about it, or calculating it in meters) how far

500 centemeters is. 2000? 20,000?

We need numbers that make sense to us in relationship to objects; we

scale up and use meters and kilometers for large numbers.


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Time for a Break! Next Up


The Electromagnetic Spectrum

Classifying Stars




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Lets check your knowledge

Please draw an electromagnetic spectrum

on a sheet of paper, and label the parts.

You can work in groups.


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Radiation

There are lots of types of light (radiation),

including visible and invisible

Electromagnetic spectrum

http://coolcosmos.ipac.caltech.edu/cosmic_classroom/ir_tutorial/what_is_ir.html

.
http://coolcosmos.ipac.caltech.edu/cosmic_classroom/ir_tutorial/what_is_ir.htmlhttp://coolcosmos.ipac.caltech.edu/cosmic_classroom/ir_tutorial/what_is_ir.html


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Lets Observe A Spectrum

What will the spectrum look like with a red

filter in front of your eyes? A blue filter?

Hypothesize and test your hypothesis.

Now lets examine the invisible parts

using our cell phones and a solar cell.


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There are different types of spectra

Continuous

Emission or Bright Line (from ionized gas, like

a nebula or a neon sign)

Absorption or dark line (from stars)

Illustration at http://imagine.gsfc.nasa.gov/docs/science/how_l1/spectra.html
http://imagine.gsfc.nasa.gov/docs/science/how_l1/spectra.htmlhttp://imagine.gsfc.nasa.gov/docs/science/how_l1/spectra.html


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Radiation

All stars emit radiation Radio, infrared, visible, ultraviolet, x-ray and even some gamma

rays

Most sunlight is yellow-green visible light or close to it

The Sun at X-ray wavelengths

Image athttp://imagine.gsfc.nasa.gov/docs/sc

ience/know_l1/sun.html

Image and info at

http://imagine.gsfc.nasa.gov/docs/teachers/gammaraybursts/imagine/page18.html
http://imagine.gsfc.nasa.gov/docs/science/know_l1/sun.htmlhttp://imagine.gsfc.nasa.gov/docs/science/know_l1/sun.htmlhttp://imagine.gsfc.nasa.gov/docs/teachers/gammaraybursts/imagine/page18.htmlhttp://imagine.gsfc.nasa.gov/docs/teachers/gammaraybursts/imagine/page18.htmlhttp://imagine.gsfc.nasa.gov/docs/science/know_l1/sun.htmlhttp://imagine.gsfc.nasa.gov/docs/science/know_l1/sun.html


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Using a Stars Spectrum

We can use a stars spectrum to classify it.

NOAO/AURA/NSF image at http://antwrp.gsfc.nasa.gov/apod/ap010530.html
http://antwrp.gsfc.nasa.gov/apod/ap010530.htmlhttp://antwrp.gsfc.nasa.gov/apod/ap010530.html


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Stellar Evolution


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Time to Create a Stellar Graph

Everyone will receive several stars

Place them on the large paper, according to

their color and their brightness

This is a version of the Hertzsprung-Russell

diagram.


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Hertzsprung-Russell Diagram

Images from

http://www.nasa.gov/centers/goddard/news/topstory/2007/spectrum_plants.html andhttp://sunearthday.gsfc.nasa.gov/2009/TTT/65_surfacetemp.php
http://www.nasa.gov/centers/goddard/news/topstory/2007/spectrum_plants.htmlhttp://sunearthday.gsfc.nasa.gov/2009/TTT/65_surfacetemp.phphttp://sunearthday.gsfc.nasa.gov/2009/TTT/65_surfacetemp.phphttp://www.nasa.gov/centers/goddard/news/topstory/2007/spectrum_plants.html


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Youngstars

form in

nebulae

from Small

MagellanicCloud

Image athttp://hubblesite.org/newscenter/archive/releases/2007/04/image/a/results/50/


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Star-forming region in the Large Magellanic Cloud:

http://hubblesite.org/newscenter/archive/releases/2008/31/image/a/results/50/


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Interstellar eggs

Movie at http://www.stsci.edu/EPA/PR/95/44/M16.mpg
http://www.stsci.edu/EPA/PR/95/44/M16.mpghttp://www.stsci.edu/EPA/PR/95/44/M16.mpg


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Our Sun is a Regular/ Small Star

Image at http://www.gsfc.nasa.gov/topstory/20011210insidesun.html

On the Main Sequence
http://www.gsfc.nasa.gov/topstory/20011210insidesun.htmlhttp://www.gsfc.nasa.gov/topstory/20011210insidesun.html


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In a few Billion years Red

Giant

Image at http://hubblesite.org/newscenter/archive/releases/1997/26/image/a/
http://hubblesite.org/newscenter/archive/releases/1997/26/image/a/http://hubblesite.org/newscenter/archive/releases/1997/26/image/a/


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Our Suns Habitable Zone

Billions of years ago, things may have

been different

The Sun was cooler (by up to 30%!)

Earths atmosphere was different (thicker,carbon dioxide)

Conditions will be different in the

future

By many accounts, increases in the Suns

temperature will make Earth uninhabitable

in 1 billion years or less

These changes will also affect other

planets Mars?

Animation athttp://www.nasa.

gov/97994main

_BHabitableZon

e.MPG
http://www.nasa.gov/97994main_BHabitableZone.MPGhttp://www.nasa.gov/97994main_BHabitableZone.MPGhttp://www.nasa.gov/97994main_BHabitableZone.MPGhttp://www.nasa.gov/97994main_BHabitableZone.MPGhttp://www.nasa.gov/97994main_BHabitableZone.MPGhttp://www.nasa.gov/97994main_BHabitableZone.MPGhttp://www.nasa.gov/97994main_BHabitableZone.MPGhttp://www.nasa.gov/97994main_BHabitableZone.MPG


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By 5 billion years White

Dwarf

Image at http://hubblesite.org/newscenter/archive/releases/nebula/planetary/1998/39/results/50/

Small, but very hot
http://hubblesite.org/newscenter/archive/releases/nebula/planetary/1998/39/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/planetary/1998/39/results/50/


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Image at

http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2000/28/image/a/format/web_print/results/50/
http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2000/28/image/a/format/web_print/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2000/28/image/a/format/web_print/results/50/


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Image at http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2004/27/image/a/format/large_web/results/50/
http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2004/27/image/a/format/large_web/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2004/27/image/a/format/large_web/results/50/


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Massive

Stars are

different

Image from

http://hubblesite.org/newscenter/archive/releases/nebula/emission/1997/33/results/50/

On the Main

Sequence but

not for long

l d i
http://hubblesite.org/newscenter/archive/releases/nebula/emission/1997/33/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/emission/1997/33/results/50/


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Image from http://hubblesite.org/newscenter/archive/releases/star/massive%20star/1996/04/image/a/results/50/

BetelgeuseRed Supergiant

i
http://hubblesite.org/newscenter/archive/releases/star/massive%20star/1996/04/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/star/massive%20star/1996/04/image/a/results/50/


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SupernovaMassive Star

Explodes

Images at

http://hubblesite.org/newscenter/archive/releases/star/supernova/2004/09/results/50/

http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/

http://chandra.harvard.edu/photo/2009/casa/
http://hubblesite.org/newscenter/archive/releases/star/supernova/2004/09/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/http://chandra.harvard.edu/photo/2009/casa/http://chandra.harvard.edu/photo/2009/casa/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/http://hubblesite.org/newscenter/archive/releases/star/supernova/2004/09/results/50/


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Neutron Star or Pulsar

Image at http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2002/24/results/50/
http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2002/24/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2002/24/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2002/24/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2002/24/results/50/


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Black Hole

Image at http://hubblesite.org/newscenter/archive/releases/2002/30/image/a/results/50/


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Galaxies

come in different sizes (dwarf, large, giant)

come in different shapes and classifications

SpiralsEllipticals

Lenticulars

Irregulars

are fairly close together, relative to theirsizes


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Spiral Galaxies

have flat disk, spiral arms, central bulge, and a

surrounding halo

some have a barred bulge

are fairly large (no dwarf spirals)

have lots of gas and dust and younger stars in their

arms, but older stars and little gas or dust in their

halos and central bulges


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Galaxies

Image at http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2005/01/results/50/


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Spiral galaxy--Andromeda

NOAO/AURA/NSF Images at http://www.noao.edu/image_gallery/html/im0606.html andhttp://www.noao.edu/image_gallery/html/im0685.html
http://www.noao.edu/image_gallery/html/im0606.htmlhttp://www.noao.edu/image_gallery/html/im0685.htmlhttp://www.noao.edu/image_gallery/html/im0685.htmlhttp://www.noao.edu/image_gallery/html/im0606.html


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Spiral

Galaxy

onEdge

Image at http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2006/24/image/a/results/50/
http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2006/24/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2006/24/image/a/results/50/


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Elliptical galaxies

range from spherical to football shaped

range from very small to giant

have very little gas or dust

mostly old stars

similar to the central bulge of a spiral galaxy


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Elliptical Galaxies

Images at http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/and http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/
http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/


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Lenticular

have a disk but no arms

have little or no excess gas and dust

Image at http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2002/07/results/50/
http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2002/07/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2002/07/results/50/


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Irregular Galaxies

any galaxy that isnt a Spiral, Elliptical, or

Lenticular

usually have lots of gas and dust and youngstars

may have a distorted shape from interaction

with another galaxy


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Irregular Galaxies

NASA and NOAO/AURA/NSF Images at

http://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/ ,http://www.noao.edu/image_gallery/html/im0560.html , and http://www.noao.edu/image_gallery/html/im0993.html
http://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/http://www.noao.edu/image_gallery/html/im0560.htmlhttp://www.noao.edu/image_gallery/html/im0993.htmlhttp://www.noao.edu/image_gallery/html/im0993.htmlhttp://www.noao.edu/image_gallery/html/im0560.htmlhttp://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/


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Collisions!

We now think that galaxies in groups and

clusters often collide

The Milky Way is moving at 300,000 mphtoward the Andromeda Galaxy

They may collide in about 5 billion years

Stars dont usually collide

New orbits, gas piles up to form new stars


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Interacting

Image from http://hubblesite.org/newscenter/archive/releases/galaxy/interacting/2000/34/results/50/
http://hubblesite.org/newscenter/archive/releases/galaxy/interacting/2000/34/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/interacting/2000/34/results/50/


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the Antennae or Mice

Information at http://hubblesite.org/newscenter/archive/releases/galaxy/interacting/1997/34/results/50/

The occasional results of two
http://hubblesite.org/newscenter/archive/releases/galaxy/interacting/1997/34/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/interacting/1997/34/results/50/


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Images from http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2002/21/image/a/results/50/ andhttp://hubblesite.org/newscenter/archive/releases/galaxy/spiral/1999/16/image/a/results/50/

The occasional results of two

galaxies colliding: ringed

galaxies

V i l i
http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2002/21/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/1999/16/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/1999/16/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2002/21/image/a/results/50/


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Various galaxies(can you identify types?)

Image at

http://hubblesite.org/newscenter/archive/releases/galaxy/cluster/1999/31/results/50/
http://hubblesite.org/newscenter/archive/releases/galaxy/cluster/1999/31/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/cluster/1999/31/results/50/


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Supermassive black holes

almost every medium to large galaxy weve checkhas a supermassive black hole at the center

the larger the galaxy, the more massive the black

hole

we dont know which comes first, the galaxy orthe black hole

we think that these black holes are responsible forsome of the galaxies with jets and lobes whichgive off radio waves, x-rays, etc.

Active


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Active

galaxy



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at the center of a large galaxy

Image at http://hubblesite.org/newscenter/archive/releases/exotic/black-hole/1998/22/results/20/ and

http://hubblesite.org/newscenter/archive/releases/exotic/black%20hole/2000/21/image/a/format/web_print/results/20/
http://hubblesite.org/newscenter/archive/releases/exotic/black-hole/1998/22/results/20/http://hubblesite.org/newscenter/archive/releases/exotic/black%20hole/2000/21/image/a/format/web_print/results/20/http://hubblesite.org/newscenter/archive/releases/exotic/black%20hole/2000/21/image/a/format/web_print/results/20/http://hubblesite.org/newscenter/archive/releases/exotic/black-hole/1998/22/results/20/http://hubblesite.org/newscenter/archive/releases/exotic/black-hole/1998/22/results/20/http://hubblesite.org/newscenter/archive/releases/exotic/black-hole/1998/22/results/20/


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Galaxy Clusters

the Local Group

includes the Milky Way, the Andromeda, and over

30 other smaller galaxies

the Virgo Cluster

hundreds to thousands of galaxies, 60 million light-

years away

giant elliptical at center, formed by galactic

cannibalism

the Local Group is falling toward the Virgo

Cluster at 60 to 250 miles per second!


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Coma Cluster

Image at http://hubblesite.org/newscenter/archive/releases/galaxy/cluster/2008/24/image/a/results/20/
http://hubblesite.org/newscenter/archive/releases/galaxy/cluster/2008/24/image/a/results/20/http://hubblesite.org/newscenter/archive/releases/galaxy/cluster/2008/24/image/a/results/20/


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Superclusters!

clusters are bound together in larger structures, called

superclusters

these superclusters have been mapped, and are groupedinto long strings

300 million to a billion light-years long

100 to 300 million light-years wide

and only 10 to 30 million light-years thick

in between these strings are huge voids of galaxies,

although some astronomers may have detected hot gas


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Evolution of Galaxies

Image at http://www.galex.caltech.edu/media/glx2007-05f_img01.html

Origin of the Universe
http://www.galex.caltech.edu/media/glx2007-05f_img01.htmlhttp://www.galex.caltech.edu/media/glx2007-05f_img01.htmlhttp://www.galex.caltech.edu/media/glx2007-05f_img01.htmlhttp://www.galex.caltech.edu/media/glx2007-05f_img01.html


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Origin of the Universe

Big Bang

Dominant scientific theory about the

origin of the universe

Occurred ~13.7 billion years ago

What is the Big Bang?

How do we know?


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What is the Big Bang?

Infinitely dense point

not governed by our

physical laws or time

All matter and energy

contained in one point

Image from http://www.newscientist.com/articleimages/dn11799/0-did-

antimatter-factory-spark-brightest-supernova.html

Building a Universe
http://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/0-did-antimatter-factory-spark-brightest-supernova.htmlhttp://www.newscientist.com/articleimages/dn11799/1-did-antimatter-factory-spark-brightest-supernova.html


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Building a Universe

Instantaneous filling of

space with all matter

History of the


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History of the

Universe

10-43 seconds - gravity separates from other forces

10-35 to 10-32 seconds - fundamental particles - quarks and electrons

10-6 seconds - quarks combine into protons and neutrons

1 second - electromagnetic and weak nuclear forces separate3 minutes - protons and neutrons combine into atomic nuclei

105

years - electrons join nuclei to make atoms; light is emitted105-109 years - matter collapses into clouds, making galaxies and stars

Orion Nebula - http://stardate.utexas.edu/resources/ssguide/planet_form.html
http://stardate.utexas.edu/resources/ssguide/planet_form.htmlhttp://stardate.utexas.edu/resources/ssguide/planet_form.html


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Image from http://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.html
http://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.htmlhttp://dsc.discovery.com/space/top-10/strange-universe/space-10-weirdest-things-universe-10.html


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Later History

Image at http://www.galex.caltech.edu/media/glx2004-01r_img02.html
http://www.galex.caltech.edu/media/glx2004-01r_img02.htmlhttp://www.galex.caltech.edu/media/glx2004-01r_img02.htmlhttp://www.galex.caltech.edu/media/glx2004-01r_img02.htmlhttp://www.galex.caltech.edu/media/glx2004-01r_img02.html


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Big Bang Theory

Image at http://map.gsfc.nasa.gov/universe/bb_theory.html

In 1915, Albert Einstein concluded that theuniverse could not be static based on hisrecently-discovered theory of relativity andadded a "cosmological constant" to the

theory of relativity because astronomersassured him that the universe was static

Aleksandr Friedmann and Abbe GeorgeLeMaitre are credited with developing the

basics of the Big Bang model between 1922

and 1927; their calculations suggested thatuniverse is expanding, not static.

Years later, Einstein called his cosmologicalconstant the biggest mistake of his career
http://map.gsfc.nasa.gov/universe/bb_theory.htmlhttp://map.gsfc.nasa.gov/universe/bb_theory.htmlhttp://map.gsfc.nasa.gov/media/ContentMedia/einst_8s.jpg


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Expanding Universe

In 1929, Edwin Hubble showed that most

galaxies are red-shifted (moving away

from us), and that a galaxys velocity is

proportional to its distance (galaxies that

are twice as far from us move twice as

fast)

Image from http://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/origin_destiny.html
http://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/origin_destiny.htmlhttp://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/origin_destiny.html


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Hubbles Evidence

Doppler shifting - wavelength emitted by something moving away

from us is shifted to a lower frequency

Sound of a fire truck siren - pitch of the siren is higher as the fire

truck moves towards you, and lower as it moves away from you

Visible wavelengths emitted by objects moving away from us are

shifted towards the red part of the visible spectrum

The faster they move away from us, the more they are redshifted.

Thus, redshift is a reasonable way to measure the speed of anobject.

When we observe the redshift of galaxies, almost every galaxy

appears to be moving away from usthe Universe is expanding.

Predictions for the Big Bang


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Predictions for the Big Bang

Model

The expansion of the Universe

Edwin Hubble's 1929 observation that galaxies were generally

receding from us provided the first clue that the Big Bang theory

might be right.

The abundance of the light elements H, He, Li

The Big Bang theory predicts that these light elements should have

been fused from protons and neutrons in the first few minutes after

the Big Bang.

The cosmic microwave background (CMB) radiation The early universe should have been very hot. The cosmic

microwave background radiation is the remnant heat leftover from

the Big Bang.
http://map.gsfc.nasa.gov/universe/bb_tests_exp.htmlhttp://map.gsfc.nasa.gov/universe/bb_tests_ele.htmlhttp://map.gsfc.nasa.gov/universe/bb_tests_cmb.htmlhttp://map.gsfc.nasa.gov/universe/bb_tests_cmb.htmlhttp://map.gsfc.nasa.gov/universe/bb_tests_ele.htmlhttp://map.gsfc.nasa.gov/universe/bb_tests_exp.html


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Evidence for Big Bang

Red shift - as light from distant galaxies approach earth there is an

increase of space between earth and the galaxy, which leads to

wavelengths being stretched

In 1964, Arno Penzias and Robert Wilson, discovered a noise of

extraterrestrial origin that came from all directions at once -

radiation left over from the Big Bang

In June 1995, scientists detected helium in the far reaches of the

universe - consistent with an important aspect of the Big Bang

theory that a mixture of hydrogen (75%) and helium (25%) was

created at the beginning of the universe

Wh Did h U i F ?


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When Did the Universe Form?

~13.7 billion years ago

How do we know?

Spreading (Red Shift) -

know distances, rates of

retreat, relative positions

Pervasive background

radiation of 2.7C above

absolute zero - afterglow

of the Big Bang

http://timeline.aps.org/APS/resources/85_06a.jpg

Cosmic background radiation

temperature on celestial sphere

db k i


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Feedback, Questions

Reach us online at http://www.lpi.usra.edu/education/

For more information, contact

Christine ShuplaLunar and Planetary Institute

3600 Bay Area Blvd

Houston, TX 77058

(281) 486-2135

[email protected]
mailto:[email protected]:[email protected]

Documents

starsGalaxies.ppt