Astronomy for beginners Astronomy for beginners

GalaxiesGalaxies

By Aashman VyasBy Aashman Vyas

What are galaxies?What are galaxies?

Galaxies are incredibly huge collections of stars, Galaxies are incredibly huge collections of stars, dust and gas. They usually contain several dust and gas. They usually contain several million to over a trillion stars and can range in million to over a trillion stars and can range in size from a few thousand to several hundred size from a few thousand to several hundred thousand light-years across. There are hundreds thousand light-years across. There are hundreds of billions of galaxies in the universe. Galaxies of billions of galaxies in the universe. Galaxies come in many different sizes, shapes and come in many different sizes, shapes and brightnesses and, like stars, are found alone, in brightnesses and, like stars, are found alone, in pairs, or in larger groups called clusterspairs, or in larger groups called clusters

Types of galaxiesTypes of galaxies

There are many different types of galaxies:There are many different types of galaxies:SpiralSpiralEllipticalElliptical Irregular Irregular Barbed spirals Barbed spirals Etc.Etc.But I will be concentrating on the first three But I will be concentrating on the first three

since they are the main types of galaxiessince they are the main types of galaxies

How do elliptical galaxies form?How do elliptical galaxies form?Scenario1 Scenario1

-Two spiral galaxies collide-Two spiral galaxies collide

-Their Super-massive blackholes merge with -Their Super-massive blackholes merge with each other (see my blackhole PowerPoint) each other (see my blackhole PowerPoint)

-Disturbance + collision disrupt spiral arms -Disturbance + collision disrupt spiral arms of galaxy merging themof galaxy merging them

-New galaxy has rings instead of arms-New galaxy has rings instead of arms

-Elliptical galaxy -Elliptical galaxy

How do elliptical galaxies form?How do elliptical galaxies form?Scenario2Scenario2

One spiral galaxyOne spiral galaxyLots of satellite galaxies bombard spiral Lots of satellite galaxies bombard spiral

armsarmsThey disrupt spiral shapeThey disrupt spiral shapeArms become ringsArms become ringsElliptical galaxyElliptical galaxy

How do irregular galaxies form?How do irregular galaxies form?

Simple answer:Simple answer:When any type of galaxies collide and if When any type of galaxies collide and if

the result doesn’t have a particular shape the result doesn’t have a particular shape it is a irregular galaxyit is a irregular galaxy

Bibliography Bibliography

Ask an astronomer (for kids)Ask an astronomer (for kids)WikipediaWikipediaYahoo answers Yahoo answers Astronomy.com Astronomy.com Ask the vanAsk the vanThe big book of stars and planets by The big book of stars and planets by

Robin Kerrod Robin Kerrod

Thank You For WatchingThank You For Watching