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
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