Sep 28 John R. Spencer (Southwest Research Institute)Sep 28 John R. Spencer (Southwest Research Institute)

““Taking the Measure of the Solar System”Taking the Measure of the Solar System”

Oct 05 Carl Heiles (Berkeley)Oct 05 Carl Heiles (Berkeley)

““Our Local Microcosmos”Our Local Microcosmos”

Oct 19 Mario Mateo (Michigan)Oct 19 Mario Mateo (Michigan)

““Galaxies: Where Space Becomes Time”Galaxies: Where Space Becomes Time”

Nov 02 Niel Brandt (Penn State)Nov 02 Niel Brandt (Penn State)

““A Rich and Evolving Tapestry of Cosmic A Rich and Evolving Tapestry of Cosmic Structure”Structure”

Nov 16 Michael S. Turner (Chicago) Nov 16 Michael S. Turner (Chicago) Mohler Prize LectureMohler Prize Lecture

““Quarks to the Cosmos: Connecting the Quarks to the Cosmos: Connecting the Smallest and Largest Scales”Smallest and Largest Scales”

Scales of the UniverseScales of the Universea distinguished speaker seriesa distinguished speaker series

7:30 PM, 1800 Dow Chemistry BulidingTelescope observing / planetarium show following

NGC 3310

NGC 1300

NGC 5866

M 104

M 83

NGC 3370

NGC 2787

Center of M 51

Galaxies: Where Space

Becomes Time The 20th Century Heritage:

A Galaxy is our (essential) Home.

Ours is a Universe of Galaxies.

. . . S C A L E

Dwarf Galaxies

• M ~ 107 M

•L ~ 105 L

• R ~ 1000 l-y

• N ~ 105

Dwarf Galaxies

• M ~ 107 M

•L ~ 105 L

• R ~ 1000 l-y

• N ~ 105

‘Normal’ Galaxies

• M ~ 1012 M

•L ~ 3 x 1010 L

• R ~ 100,000 l-y

• N ~ 1012

‘Normal’ Galaxies

• M ~ 1012 M

•L ~ 3 x 1010 L

• R ~ 100,000 l-y

• N ~ 1012Giant Galaxies

• M ~ 1013-14 M

•L ~ 5 x 1011 L

• R ~ 1 million l-y

• N ~ 1015

Giant Galaxies

• M ~ 1013-14 M

•L ~ 5 x 1011 L

• R ~ 1 million l-y

• N ~ 1015

But what do these numbers mean?

1 billion sec (109 sec)

1 trillion inches (1012 in)

1 quadrillion grains of sand (1015)

The Galactic Disk

Where stars are born today

Where most stars live outtheir lives.

Where most stars die andrecycle their ashes.

The Galactic Bulge

The higheststellar densityin our Galaxy

A surprising haven of massive star formation (Galactic Bar?)

Home of a super-massiveBlack Hole at the Galactic

Center

The Galactic HaloNGC6093

47 Tuc

Our Milky Way

(side view)

Really, NGC 891

Oldest Humans (60k)

Neanderthals disappearing (45k)

Humans cross Bering Strait to NA (17k)

Egyptian Civilization develops (8k)

Present day

The Progression of Time in a Galaxy Photo

But Galaxies like the Milky Way are just individual players on the stage of the Universe. . . How big is the stage?

Distances

Nearby Galaxies: ‘Normal’Variable Stars

Remote Galaxies: Supernovae

Distribution

Evolution

v = HD

We see >10 billion yrs into the past:

There were more galaxies!They were closer together!!

Galaxies would have first grown from collapse, then merging.We can see that long-past era today . . .

Collisions/Mergers

. . . even in the Milky Way!

and the processes at work then are still going on . . .

It may have looked something like this . . .

Earth (0.000001 sec away)

Meteor (0.00001 sec)

Comet McNaught (15 min)

Alpha Centauri (4.2 yrs)

Milky Way (28,000 yrs)

47 Tuc (12000 yrs)

SMC (250,000 yrs)

Dark Sky (14 billion yrs)