GALAXIES
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GALAXIES
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GALAXIES. Do Now. Take a sheet of paper and answer the following questions. What are two kinds of visible light telescopes scientists use to gather information from space? When we see stars in the sky, how is it like looking back in time? . Sirus. Approximately 8.5 light-years away - PowerPoint PPT Presentation
Transcript of GALAXIES
GALAXIES
Do NowTake a sheet of paper and answer the
following questions.
What are two kinds of visible light telescopes scientists use to gather information from space?
When we see stars in the sky, how is it like looking back in time?
Sirus
Approximately 8.5 light-years away
Light-year: 6 trillion miles
Galaxies Goal:
I can analyze how galaxies are classified. I can identify characteristics of our Milky
Way galaxy.
Lab Group Classification Activity Discuss classifications and re-group Tree map notes Exit Ticket Galaxy Homework
GalaxiesGalaxies are huge groupings of stars,
gas and dust held together by gravity.
Galaxies differ greatly in size. Some contain a hundred million stars to
the largest containing more than a trillion stars!
Scientists classify galaxies.
Lab Activity The Hubble Space Telescope has just
received exciting new images of 30 galaxies. Your job is to work with your team of scientists to classify these galaxies.
Classify the 30 galaxies in your envelope whatever kind of groups you decide. You must provide reasoning for your
classification. You must record decisions in your science
notebook.
Galaxies
Scientists classify into 3 categories by shape
Spiral Elliptical Irregular
Galaxies Spiral galaxies have arms of stars, gas and dust that curve away from the centerin a spiral or pinwheel pattern.
Spiral galaxies are disk-shaped, have a bulge in the center.
Most of the stars in the disk & bulge are older stars. However, the spiral arms within the disk contain many young, bright stars.
Galaxies In addition to the spiral galaxy, there
is a barred spiral. This type of galaxy is similar in make-up to a spiral galaxy but seems to have its arms connected or linked by a bar.
Galaxies Elliptical galaxies are shaped like
spheres to football or egg-shaped. Unlike spiral galaxies, elliptical galaxies have almost no dust or gas between stars and all of their stars are old.
Galaxies Irregular
galaxies are galaxies without a definite shape. They are generally smaller than the other type of galaxies and contain fewer stars.
Galaxies
Work with your team to reclassify your galaxies.
Distinguish between barred spiral and spiral galaxies.
Spiral Barred Spiral Elliptical Irregular
Spiral Barred Spiral
Elliptical Irregular
2, 5, 8, 10, 15, 16, 18, 19, 21, 25, 28, 7, 14, 20
ES: 7, 14, 20
9, 27, 30 3, 6, 13, 23, 26
1, 4, 11, 12, 17, 22, 24, 29
Spiral Barred Spiral
Elliptical Irregular
*Pinwheel Shape*Arms of stars, gas, and dust that curve away from center Has bulge in center and disk-shaped
Most stars in disk are old
Spiral arms have more young stars
*Similar to Spiral galaxy
*Arms connected by bar in center
Young and old stars are present
*Shaped like spheres or eggs
*Mostly old stars present
Almost no dust or gas
*No definite shape
*Smaller than other galaxies with fewer stars
Young and old stars are present
Contains gas and dust
GalaxiesGalaxies are huge groupings of stars,
gas, planets, and dust held together by gravity.
Galaxies The Earth lies within the Milky Way Galaxy.
The Milky Way is a spiral galaxy and is 100,000 light years across.
The bulge of densely packed stars at the center is approximately 26,000 light years away from the sun.
The stars in the Milky Way orbit the galaxy’s center at very high speeds, still it takes our solar system about 250 million years to complete one orbit. The age of the Milky Way has been calculated to be about 13 billion years old.
Galaxies
It’s all about perspective
Galaxies Most large galaxies seem to have super
massive black holes at their centers. At the center of the Milky Way is theorized to be a black hole with the mass of about 3 million times that of the sun.
A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
Galaxies The center of some
galaxies look very bright. This brightness is attributed to quasars.
Quasar stands for quasi-stellar which means “seeming like a star.” Quasars eject hot gas from their centers giving off a very bright light.
Galaxies
Goal: I can analyze how galaxies are classified. I can identify characteristics of our Milky
Way galaxy
Exit Ticket1. What kind of galaxy is shown in image #1? 2. What kind of galaxy is shown in image #2? 3. What kind of galaxy is shown in image #3?4. What kind of galaxy is shown in image #4?5. What is the name of our galaxy and what shape is it?6. Bonus: Name one characteristic of each of the galaxies in
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Exit Ticket 2/12 Name _________________________
1. What kind of galaxy is shown in image #1? ________________2. What kind of galaxy is shown in image #2? ________________3. What kind of galaxy is shown in image #3? ________________4. What kind of galaxy is shown in image #4? ________________5. What is the name of our galaxy? ________________________
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