Document4.pdf - 17 - Our Milky Way - Structure Structure of...

This preview shows page 1 - 2 out of 5 pages.

17 - Our Milky Way - StructureStructure of the Milky Way- Refers to the band of light which can be seenspanning the sky on a dark night.- Further studies revealed the Milky Way to be a vastsystem containing billions of stars, as well as cloudsof dust and gas.- Dark regions are clouds of dust - obscure our view ofthe stars- As a result we can't see all of our galaxy at visiblewavelengths.- Contains a lot of dust.Components- Centre → bright region of stars called the bulge.- Spiral arms: made from gas and stars.- Disk of stars is very thin - 100k light years across +1k light years thick.- Halo - extended region of stars.- Globular clusters - clusters of millions of stars.The orbits of stars- Radial velocity - velocity of a star along our line-of-sight direction using Doppler effect.- Red-shifted or blue-shifted- Proper motion - motion of a star perpendicular to our line-of-sight using astrometry.- From these measurements we can determine the orbits of various types of stars.

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 5 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
One
Professor
N/A
Tags
galactic centre

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture