caty pilachowski mini-university 2013 our milky way in space and time

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Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

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Page 1: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Caty PilachowskiMini-University 2013

Our Milky Way in Space and Time

Page 2: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Our Journey…Where in the Galaxy Are We?The Local NeighborhoodTop Milky Way Destinations!The Dark Heart of the GalaxyFormation of the Milky WayOur Galaxy in the Cosmos

Page 4: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

A Thin Disk of Stars

100,000 Light Years

100,0

00 L

igh

t Years

Page 5: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

What Is a Light Year?

The distance light travels in one year (about 6 trillion miles)

Light travels at 186,000 miles per secondThe Moon is

1 light-second from

Earth

The Sun is 8 light-minutes

from Earth

The nearest star, Proxima Centauri,

is four light years from the Sun

Page 6: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Disk

Bulge

Halo

Hot Young Stars

Spiral Arms

Dust Lanes

Galactic Center

The Sun

Light takes 100,000 years to cross the Milky Way

Our Home

Page 7: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Meet the Neighbors

Proxima Centauri Alpha/Beta Centauri Most nearby stars are

small, dim and cool

Page 18: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

The Galactic

Center in Infrared

LightThe dust is transparent to infrared light, and we can see through the gas and dust to observe the Galactic Center

Page 20: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Massive Black Hole!

• Detected in infrared, radio, and x-ray light

• Mass 4 million times the Sun’s mass

• Growing slowly through accretion

• All big galaxies host central black holes

Page 22: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

The Universe Contains

Many Spiral Galaxies

We learn about our Milky Way from other galaxies

Page 23: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Forming the Milky Way

Galaxies like the Milky Way form from the consolidation of many primordial gas clouds

Collisions of gas clouds

create bursts of star

formation to shape the

Galaxy

Page 24: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

The Milky Way Is Still Growing

Nearby dwarf galaxy discovered in 1994 in the direction of Sagittarius

Distance about 88,000 light yearsMerging with the Milky Way

Page 25: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Galaxy’s

“New”Tidal

Stream

Sagittarius orbits the Milky WayThe orbital period is about a billion years“Tidal stream” of stars from Sagittarius

circles the Milky Way

Page 26: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

The Local Grou

pThe Milky Way is

part of a small group of galaxies known as the local group

Andromdea GalaxyMilky Way GalaxyTriangulum GalaxyMany small ones

2.5 million light years

Page 27: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Galaxy Collision!

Page 28: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

The Local Group Is Part of an EVEN BIGGER Group

The Local Group is part of the Virgo Super Cluster of Galaxy Groups

Page 29: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Newly Discovered Galaxy!

The Leo P galaxy was just discovered here at IU using the WIYN Telescope

Five million light years from the Milky Way

Undisturbed, in an empty part of nearby space

Page 30: Caty Pilachowski Mini-University 2013 Our Milky Way in Space and Time

Our Home in the Cosmos