What is galaxy and how many different kinds are there?

By: Flavio Gutierrez

What is a Galaxy?MassiveConsists of:

StarsDustDark matter

ContainsPlanetsStarsMoon

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Big Bang TheoryCosmological Model13.8 billion years agoHow the universe started

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Types of Galaxies Types of Galaxies

Elliptical Spiral IrregularBarred Spiral

 Hubble Sequence

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Elliptical GalaxyEllipsoidal profileLittle interstellar matterSmaller globular clusterLargest GalaxyExamples:

Maffei 1Centaurus A (NGC 5128)M32M49M59M60 (NGC 4649)M87 (NGC 4486)M90M105 (NGC 3379)

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Spiral GalaxyVery visible starsMost beautifulDesign is spiralExamples:

Milky WayAndromedaWhirlpoolTriangulumSunflowerPinwheel

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Irregular GalaxyNo shapeNot in any class of Hubble sequenceExamples:

 Magellanic Cloud galaxy

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Barred Spiral GalaxyIs a spiral galaxy with central bar shapeCompose of starsExamples are:

NGC 1300Sculptor GalaxyM58M91M95M109NGC 1365NGC 2217Magellanic Clouds

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Lists of GalaxiesThere are trillions of galaxies in the worldMilky Way is one the galaxies

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References http://en.wikipedia.org/wiki/Galaxy#mediaviewer/File:NGC_4414_(NASA-med).jpg http://en.wikipedia.org/wiki/Galaxy http://en.wikipedia.org/wiki/Galaxy#Types_and_morphology http://apod.nasa.gov/apod/image/0406/m87_cfht.jpg http://en.wikipedia.org/wiki/Spiral_galaxy#mediaviewer/File:UGC_12158.jpg http://en.wikipedia.org/wiki/Irregular_galaxy#mediaviewer/

File:Irregular_galaxy_NGC_1427A_(captured_by_the_Hubble_Space_Telescope).jpg http://en.wikipedia.org/wiki/Irregular_galaxy#mediaviewer/

File:Irregular_galaxy_NGC_1427A_(captured_by_the_Hubble_Space_Telescope).jpg http://en.wikipedia.org/wiki/Barred_spiral_galaxy#mediaviewer/File:Hubble2005-

01-barred-spiral-galaxy-NGC1300.jpg http://en.wikipedia.org/wiki/Barred_spiral_galaxy#mediaviewer/File:Hubble2005-

01-barred-spiral-galaxy-NGC1300.jpg http://en.wikipedia.org/wiki/Big_bang_theory#mediaviewer/

File:Universe_expansion2.png http://en.wikipedia.org/wiki/Big_bang_theory http://en.wikipedia.org/wiki/List_of_galaxies http://en.wikipedia.org/wiki/List_of_galaxies