How Do Stars Move through the Galaxy

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Slide 1

The Milky Way

Our Galactic Home

Slide 2

Slide 3

Goals

Structure of our Galaxy.

Its size and shape.

How do stars and things move through it?

Mass and Dark Matter.

The Galactic Center.

Slide 4

The Milky Way

Stars

Dust

Gaseous Nebulae

Open Clusters

Globular Clusters

Pulsars

Black Holes

How do they all fit together to make our galaxy?

Slide 5

Optical emission from stars and nebulae

Slide 6

Near-Infrared stellar emission – copyright E. L. Wright and COBE

Slide 7

Far-Infrared dust emission – copyright E. L. Wright and COBE

Slide 8

Radio emission from neutral hydrogen – copyright J. Dickey

Slide 9

X-ray emission from hot gas – copyright S. Digel and ROSAT

Slide 10

Gamma-ray emission from pulsars and black holes – copyright NASA

Slide 11

Where are We?

We aren’t at the center of the Milky Way.

Where is the center then?

Globular Clusters point the way.

M10 – copyright Credner and Kohle

Slide 12

You Are Here

Slide 13

Slide 14

Near-Infrared stellar emission – copyright E. L. Wright and COBE

Slide 15

Galactic Distances

How do we know the distance to stars and clusters in our galaxy?

Trigonometric parallax good out to 100 pc.

We believe galaxy is ~30 kpc wide.

How do we know?

Slide 16

Spectroscopic Parallax

If you know how luminous a star REALLY is and how bright it looks from Earth, you can determine how far away it must be to look that faint.