Post on 04-Apr-2018
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Astronomy C - Variable Stars
A. Pulsating Variables:1) Long Period Variables
a) Mira type
b) Semiregular2) Cepheids
3) RR Lyrae
4) RV Tarui
B. Cataclysmic (Eruptive) Variables:1) T Tauri
2) Novae
3) Dwarf Novae4) Recurrent Novae
5) Supernovae
a) Type IIb) Type Ia
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Astronomy C - Variable Stars
A. Pulsating Variables:1) Long Period Variables
a) Mira type Mira
b) Semiregular Betelgeuse2) Cepheids Delta Cephei
3) RR Lyrae [Globular Clusters]
4) RV Tarui R Scuti
B. Cataclysmic (Eruptive) Variables:1) T Tauri [Protostars]
2) Novae GK Persei, Nova Aquilae
3) Dwarf Novae Z Cam, SS Cygni4) Recurrent Novae [between Dwarf and Nova]
5) Supernovae
a) Type II Cas A, SN 1987A, DEM L316b) Type Ia Tychos SNR, DEM L316
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Light Curves Variation over Time
Maximum (Maxima)
Minimum (Minima) Period
Apparent Magnitude vs Julian Day
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A. Pulsating Variable Stars;
1) Long Period Variables (LPVs)a) Miras
Omicron Ceti (Mira)
b) Semiregular Variables
80 1000 days, 2.5 5.0
mag
Betelgeuse
(Alpha Orionis)
30 1000 days, 1.0 2.0
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Mira
Instability Strip
Semiregular
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2) Cepheid Variable Stars
Delta Cephei
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2) Cepheids [ Periods of 1 70 days, 1.0 2.0 mag]
Delta Cephei
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A Cepheid Variable Star in M100
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3) RR Lyrae Variable Stars
Periods of a few hours to one day, .3 2.0mag
47 Tuc
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C h id d RR L V i bl St
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Cepheid and RR Lyrae Variable StarsPeriod-Luminosity Relationship and The Distance Modulus:
[Mv = 0.75]
M = m - 5log10 (r)10
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4) RV Tauri a Stellar Missing Link?
R Scuti
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Mira
Instability Strip
Semiregular
Cepheid
Instability Strip
RR Lyrae
B C t l i (E ti ) V i bl
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B. Cataclysmic (Eruptive) Variables
1) T Tauri; proto-star stage for
mid-sized stars
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Stellar Nurseries
- sites of protostar
& T-Tauri formation
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M 42 The Orion Nebula
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2) Novae
Close binary systems main sequence star & a whitedwarf
1 to 300 days, 7.0 16.00 mags
Novae:
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Novae:
Nova Aquilae
GK Persei
3) Dwarf Novae
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3) Dwarf Novae
Dwarf Novae:
Close binary systems main sequence star, white dwarfand an accretion disk
Two of three subclasses; U Gem SS Cygni
Z Cam Z Cam
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SS Cygni
Dwarf Novae:
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Dwarf Novae:
SS Cygni
Z Cam
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4) Recurrent NovaeClose binary systems main sequence star & a white
dwarf
1 to 300 days, 7.0 16.00 mags
*** Similar to novae but often resemble dwarf novae
5) Supernovae
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5) Supernovae
a) Type II
Cas A
SN 1987A
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b) Type Ia
Tychos SNR Mira
T I SDEM L316
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Type Ia Supernova
Type II Supernova
DEM L316
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MZ 3 The Ant Nebula (planetary nebula)
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(p y )
Al l B t P i
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Algol Beta Persei
Eclipsing Binary
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Cosmological Distances
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Cosmological Distances
Spectroscopic
Parallax
Variables
Cepheids
RR Lyrae
Cosmological Distances
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g
CepheidsdThe Distance Modulus: M = m - 5log10 (r)
10
Spectroscopic ParallaxThe Distance Modulus: M = m - 5log10 (r)
10
Cosmological Distances &
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Type Ia Supernovae Standard CandleCandles
Mv= -19.5
Basic Equations and Relationships
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The Distance Modulus: M = m - 5log10(r)
10
Keplers 3rdLaw: (MA + MB) = a3
p2
v = d ; a = v ; 2 a = vP ; Fc= mac ; ac= v2= r2
t t r
1 pc = 206,265 au = 3.26 ly = 3.08 x 1016m
1 = 60 arcmin = 60 ; 1 = 60 arcsec = 60
Inverse Square Law: L = 1/r2
Circumference, Area, Surface Area, and Volume of a Sphere
REARRANGE ALL EQUATIONS FOR EACH VARIABLE
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JD 2449050
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JD 2449110
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JD 2449150
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JD 2449180
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JD 2449240
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JD 2449300
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JD 2449350
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JD 2449375
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JD 2449435
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JD 2449500
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JD 2449540
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JD 2449635
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JD 2449700
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JD 2449740
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JD 2449760
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JD 2449800
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JD 2449870
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JD 2449950
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JD 2449835
43
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W Cyg
61 40
55
59
53
68
55
696967
67
64
75
74
70
JD 2449859
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W Cyg
40
53
68
55
69
55
59
43
61
64
6767
69
75
70
74
JD 2449917
43
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W Cyg
4061
53
68
55
6967
69
75
70
67
55
59
74
43
JD 2449951
43
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W Cyg
61 40
74
43
55
5953
68
55
69
67
67 69
75
70
64
JD 2449979
43
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W Cyg
61 40
74
43
55
5964
67
67
69
75
70
53
68
55
69
JD 2449991
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W Cyg
4061
64
74
43
55
5953
68
55
6967
69
75
67
70
JD 2450013
43
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W Cyg
4061
64
74
55
5953
68
55
69
67
69
75
67
70
Phase Diagrams
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1) Cepheid Light Curve
3) Same Data Plotted Twice
2) Superposition of Periods
4) Same data starting at
Maxima
Th M h Ob i
O C Diagrams(Observed minus Calculated)
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Theory Matches Observation
Perfectly Periodic
Correct Epoch
Correct Period
** The slope of each line is the difference between its period and the estimated period.
Perfectly Periodic
Correct Epoch
Wrong Period
**True Period longer
Perfectly Periodic
Change in Period
**True Period Shorter
then Lenthens
Perfectly Periodic
Correct Period
Wrong Epoch
Periodic
Period UnchangedEpoch has Changed
NOT Perfectly Periodic
Different Period
Each Day
Stellar Evolution A Journey with Chandra
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Stellar Evolution A Journey with Chandra
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Stellar Cycles Sets and Cosmic Connections Request URL:
http://chandra.harvard.edu/edu/epo/request_special.html
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Stellar Cycles Card Set:
http://www.chandra.harvard.edu/edu/epo/request.htmldonna.young@tufts.edu
http://www.tufts.edu/as/wright_center/
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Additional Resources:
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The American Association of Variable Star Observers
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http://www.soinc.org/store/TG-DVD-06v10.htm
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UPDATED COACHES MANUAL COMING SOON!!!
(AVAILABLE ONLINE AT THE NSO WEBSITE)