p

Method of Trigonometric Parallaxes

June

December

Distant Stars

ForegroundStar

Closer stars have larger parallaxes:

Distant stars have smaller parallaxes:

Sun

Sun No propermotion

Large propermotion

Proper Motions

1902

1952

2002

Barnard’s Star

Case Study: The Big Dipper

Today

50,000 BC

50,000 BC

Today

50,000 AD

No Shift

Blueshift Redshift

Radial Velocities

Sun

Space Velocity

Sun

TangentialVelocity

Radial Velocity

Proper Motion (angle)

Distance

2t

2r

2 vvv

tv 4.74 d=

SpaceVelocity

d=1

d=2

d=3

B=1

B=1/9

B=1/4

Center of Mass

M2

M1

a

a1a2

A

A

B

B

B

A

A

B

Spectroscopic Binary

Eclipsing Binary

Time

3

1

Brig

htne

ss

4

2

1

3

2

4

Hydrogen

Continuum

Absorption Lines

The Spectral Sequence

Bluest Reddest

Spectral Sequence is a Temperature Sequence

Hottest Coolest50,000K 1300K

O B A F G K M L

H–R Diagram

40,000 20,000 10,000 5,000 2,500

106

104

102

1

102

104

Temperature (K)

Lum

inos

ity (L

sun)

White Dwarfs

Giants

Supergiants

Main Sequence

Russell (1912) HIPPARCOS (1999)

HipparcosH-R Diagram

4902 single starswith distance errors of <5%

L M4

Hydrostatic Equilibrium

Gas Pressure

Gravity

Core-Envelope Structure

Hot, Compact Core

Cooler,ExtendedEnvelope

Photon Random Walk

Convection

cooler watersinks

Hot blob rises

Proton-Proton Chain:

(twice) eHpp e2

(twice) HepH 32 ppHeHeHe 433

positron

neutrino

2H

positron

neutrino

2Hphoton

3He

4He

photon

3He

CNO Cycle:12C + p N

N C e

C p N

N p O

O N e

N p C He

e

e

13

13 13

13 14

14 15

15 15

15 12 4

Main Sequence

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10-2

10-4

Temperature (K)

Lum

inos

ity (L

sun)

HighMass

LowMass

Upper Main Sequence Star

RadiativeEnvelope

ConvectiveCore

ConvectiveEnvelope

RadiativeCore

Lower Main Sequence Star

ConvectiveEnvelope

ConvectiveCore

Red Dwarf Star

20,000 10,000 5000 2500Temperature

105

103

102

0.1

0.01

104

10

1

Lum

inos

ity

(Lsu

n)

15 Msun

5 Msun

2 Msun

1 Msun

0.5 Msun

Zero-Age Main Sequence

Pre-Main Sequence Evolution

Red Giant Star

InertHe

Core

H BurningShell

Cool, ExtendedEnvelope

Climbing the Red Giant Branch

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10 -2

10 -4

Temperature (K)

Lum

inos

ity (L

sun) Main Sequence

H-core exhaustion

Red GiantBranch

Horizontal Branch Star

HeBurning

Core

H BurningShell

Envelope

Horizontal Branch

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10 -2

10 -4

Temperature (K)

Lum

inos

ity (L

sun) Main Sequence

H-core exhaustion

Red GiantBranchHorizontal Branch

HeliumFlash

Asymptotic Giant Branch Star

InertC-OCore

He BurningShell Cool, Extended

Envelope

H BurningShell

The Asymptotic Giant Branch

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10 -2

10 -4

Temperature (K)

Lum

inos

ity (L

sun) Main Sequence

H-core exhaustion

Red GiantBranchHorizontal Branch

AsymptoticGiant Branch

Planetary Nebula Phase

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10 -2

10 -4

Temperature (K)

Lum

inos

ity (L

sun)

Main Sequence

Bare Core

WhiteDwarf

Envelope Ejection

Red Supergiant Star

InertHe

Core

H BurningShell

Cool, ExtendedEnvelope

Not to Scale

Supergiant Branch

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10 -2

10 -4

Temperature (K)

Lum

inos

ity (L

sun)

RedSupergiant

Main Sequence

Blue Supergiant

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10 -2

10 -4

Temperature (K)

Lum

inos

ity (L

sun)

Blue Supergiant

HeliumFlash

Main Sequence

End of Helium Burning

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10 -2

10 -4

Temperature (K)

Lum

inos

ity (L

sun)

Main Sequence

End of Carbon Burning Phase

InertO-Ne-Mg

Core

C BurningShell

Red SupergiantEnvelope

He BurningShell

H BurningShell

End of the Silicon Burning Phase

InertFe-NiCore

Si BurningShell

O BurningShell

Ne BurningShell

C BurningShell

He BurningShell

H BurningShell

Envelope Radius: ~ 5 AU

Core Radius: ~1 Rearth

Crab NebulaRemnant of Supernova in 1054 AD

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10-2

10-4

Temperature (K)

Lum

inos

ity (L

sun)

Age: ~1 Myr

Zero AgeMain Sequence

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10-2

10-4

Temperature (K)

Lum

inos

ity (L

sun)

Age: ~10 Myr

B Stars

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10-2

10-4

Temperature (K)

Lum

inos

ity (L

sun)

Age: ~100 Myr

A Stars

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10-2

10-4

Temperature (K)

Lum

inos

ity (L

sun)

Age: ~1 Gyr

F Stars

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10-2

10-4

Temperature (K)

Lum

inos

ity (L

sun)

Age: ~10 Gyr

G Stars

Age: ~10 Myr Age: ~1 Gyr

TempBlue Red Temp

BStars

FStars

Lum

inos

ity

Typical Globular Cluster H-R Diagram

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10-2

10-4

Temperature (K)

Lum

inos

ity (L

sun)

HorizontalBranchZero-Age

MainSequence Giant

Branch

MainSequence

Sirius BM 1.0 Msun

R 5800 km

White Dwarf

Neutron Star

M=1.5 Msun

R10 km(spaceimaging.com)

Inside a Neutron Star

CrystallineIron Crust

NeutronSuperfluid

??

SuperconductingProtons

RadiationBeam

MagneticField

SpinAxis

Pulsar Model

Neutron Star vs. Black Hole

Neutron StarM=1.5 Msun

R=10 kmManhattan

(spaceimaging.com)

Black HoleM=1.5 Msun

RS=4.5 km

Jack

Jill

Spectroscopic Parallax

A8V Star

40,000 20,000 10,000 5,000 2,500

106

104

102

1

10-2

10-4

Temperature (K)

Lum

inos

ity (L

sun)

A8I Star

L = 10 Lsun

Spectral Type

L = 22,000 Lsun

Period-Luminosity Relationship

1 5 10 50

102

103

104

Period (days)

Lum

inos

ity

(Lsu

n) Cepheids

RR Lyraes

3 100300.5

Cepheid P-L Relation

Example: Cepheid with a 10-day period

1 5 10 50

102

103

104

Period (days)

Lum

inos

ity

(Lsu

n)

3 100300.5

L=5011 Lsun

P=10d

CepheidP-L Relation

Wright’s Milky Way (1750)

Manystars

Few Stars

The Herschels’ Milky Way Map (1785)

Kapteyn Model (1922)

~17 kpc

~3 kpc

kpc = kiloparsec = 1000 pc

Shapley’s Globular Cluster Distribution

3020101020 40

10

20

10

20

kpc

Hubble “Tuning Fork” Diagram

E0 E3 E7

SBa SBb SBc

Sa Sb Sc

NGC 4414Type Sc

Flocculent & Grand Design Spirals

NGC 628Type Sc

E1 E5

Elliptical Galaxies

Sa

Sb

Sc

Ordinary Spirals

SBa

SBb

SBc

Barred Spirals

Irregular Galaxies

Large Magellanic Cloud Small Magellanic Cloud

NGC 628Face-On Sc

NGC 891Edge-On Sb

Rotating Disk

Rotation Axis

Approaching SideBLUESHIFT

Receding SideREDSHIFT

Differential Rotation

Inner orbit pulls ahead

Outer orbitlags behind

Schematic Spiral Galaxy Rotation Curve

0

0

25

200

100

5 10 15 20

Radius from the Center (kpc)

Rot

atio

n S

peed

(k

m/s

ec)

Solid-BodyRotation

Differential Rotation

Observed vs. Predicted Keplerian

50

200

100

0

10 20 30 400Radius from the Center (kpc)

Rot

atio

n S

peed

(k

m/s

ec)

KeplerianPrediction

Orbit Crowding Schematic

Nested EllipticalOrbits, each oneslightly rotated.

NGC147NGC185

M32

And IIAnd III

Fornax

Scupltor SMC

Sagitarius

DracoUrsa Minor Leo II

NGC 205And I

NGC 6822

M31

M33

IC1613

LMC

MW

Carina

Leo I

The Local Group

1 Mpc

~100 Mpc

Local Group

LocalSupercluster

Data from Tully, 1982, ApJ, 257, 389

Voids

Filaments2dF Redshift Survey>120,000 Galaxies

300 Mpc

600 Mpc

Raising Tides

Far side Near side

Bright Active Galaxy

NGC 5548

Variability (1988-1996)HST Image

OSU AGN Watch

Normal Galaxy

Active Galaxy

Composite Quasar SpectrumSloan Digital Sky Survey

Jane’s clock as seen by Jane:

Tick!!

Photon Path = 3 meters

Jane’s clock as seen by Dick:

0.8c

Tick!!

Photon Path = 5 meters

Perihelion Precession of Mercury

Earlier Later

Bending of Starlight(side view)

TruePosition

Sun

ApparentPosition

Scale is exaggerated

Earth

0 0.5 1Deflection(arcsec)

1o 2o

1o

2oView from EarthData from 1922 Eclipse

Hubble’s Data (1929)

1000

500

0

0 1 2Distance (Mpc)

Rec

essi

on V

eloc

ity

(km

/sec

)

Hubble & Humason (1931)

10 20 30

5000

10,000

15,000

20,000

Rec

essi

on V

eloc

ity

(km

/sec

)

Distance (Mpc)

1929 Data

Freedman et al. (2001) – HST Key Project

Freedman et al. 2001, ApJ, 553, 47

Freedman et al. 2001, ApJ, 553, 47

Expanding Space-Time

Universe 2x largerGalaxies are 2x further apart

Recession Velocity (cz)

Dis

tanc

e (d

)

Accelerating(slower in past)

Decelerating(faster in past)

Constant

2-D Examples of Curved Spaces

Positive(Spherical)

Flat

Negative(Hyperbolic)

d L (d

ista

nce)

Dev

iatio

n fro

m

=0

, m=0

.3 m

odel

Redshift (z)

m=0.3, =0

Accelerated

Decelerated

Very Open<<1

Closed>1 Oscillating?

Time

Dis

tanc

e B

etw

een

Gal

axie

s

~100 Billion Years

Histories for =0

Critical/Open=1

Matter & Energy Content of the Universe

dm

m

Size

Binding Energy

Atoms 10–10 m 103 K Nuclei 10–14 m 1010 K p & n 10–15 m 1011 K Quarks 10–18 m 1013 K

Typical Sizes & Binding Energies

Big

Ban

g

Infla

tion

GU

Ts E

poch

Pla

nck

Epo

ch

Nuc

leos

ynth

esis

Nuc

leon

Fre

ezeo

ut

Qua

rk F

reez

eout

Ele

ctro

wea

k D

ecou

plin

g

Rec

ombi

natio

n30

0,00

0 yr

Toda

y~1

3 G

yr

Dar

k A

ges

Firs

t Sta

rs &

G

alax

ies

1 G

yr

500

Myr

Big

Ban

g0

Sun

For

ms

9 G

yr