Milky Way Galaxy Cierra Yoshikawa Tomohiro Hoshino
What is the Milky Way Galaxy? Spiral galaxy Containing 400 billion stars including our solar system Plus gas and dust x750 solar mass
What is the Milky Way Galaxy? light year in diameter Formed by the collapse of a large region of gas and dust Part of group of galaxies called the Local Group Group of 30 galaxies that are about 5 million light years across
Other Info
Milky Way Arms Perseus Arm Saittarius Arm Cygnu Arm Orion Arm (our solar system) Norma Arm Sctum-Crux Arm
3 General Components The halo Nuclear bulge The disk
The Halo Consists of the oldest stars and dark matter, absence of gas or dust 146 Globular Clusters Spherical shape Believed to be formed billion yrs ago Produces hot gas called gamma-ray halo
The Disk Contains the sun and other intermediate- to young stars (million –ten billion years old), gas and dust Approximately 300pc (1,000 light years) thick and 30kpc (100,000 light years) in diameter
The Disk Cont. Sun sits about 2/3 of the way from the center to the edge of the disk. Sun revolves around the center every 250 years
Nuclear Bulge The center of the Galaxy Dimension 1kpc by 6kpc Shaped like a football Crowded with stars which are 10 billions years old or older (population II)
Nuclear Bulge Cont. The most brightest region is called Sgr A ~ 2 x 10 6 M of Sun within 1 pc Stars are only 1000 AU apart A collision every 10 6 years
Types of Stars Population I: Younger, metal-rich stars Found in disk Population II: Older, metal- poor stars Found in halo
View from Earth Can only be seen on a clear night Looks like a band of stars splashed on the sky Can’t see spiral structure from Earth, images of structure created from computer modeling based on information from stars as they orbit the galaxy Most of it in invisible from Earth due to being in the disk 5,000-8,000 stars visible from Earth
View from Earth
Works Cited “Our Solar System in the Milky Way Galaxy.” N.p. N.d. Web. 16 April “Our own Galaxy-The Milky Way.” Cambridge Cosmology: Galaxies, N.d. Web. 16 April “The Milky Way Galaxy.” N.p. 25 Aug Web. 16 April “The Milky Way Galaxy.” University of California, San Diego Center for Astrophysics & Space Sciences, N.d. Web. 16 April