Binary Stars

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Binary Stars
2
Binary stars
orbit each other.
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Visual Binary Stars
2 Conditions Required
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Visual Binary Stars
2 Conditions Required
1-Far Apart
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Visual Binary Stars
2 Conditions Required
1-Far Apart 2-Both Bright
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Optical Double Stars
Look Like Visual Binaries Optical Illusion One
Much Farther Away
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March 1972 March 1982
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Astrometric Binary Stars
March 1972 March 1982
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Astrometric Binary Stars
March 1972 March 1982
What is required? Star Shows Measurable Motion in
Few Decades Star Relatively Close to Us
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Astrometric Binary Stars
March 1972 March 1982 March 1992
20 years 1/3 P P 60 years
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Astrometric Binary Stars
March 1972 March 1982 March 1992
a3 P2
Mgtk
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X
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Invisible Companion
Not Bright Enough to Be Seen M5M M11M M24M B
lack Hole
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Invisible Companion
Not Bright Enough to Be Seen M5M M13.5M M21.5
M Neutron Star Chandrasekhar Limit 1.4M
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Invisible Companion
Not Bright Enough to Be Seen M2lt8M Brown Dwarf
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Astrometric and Visual Binary Stars
Far Apart Both Bright Stars Shows Measureable
Motion in Only a Few Decades Close to Us
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Spectroscopic Binary
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Spectroscopic Binary
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Spectroscopic Binary
What is required? High Inclination
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Spectroscopic Binary
v v sin i
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Spectroscopic Binary
v v sin i
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PlanetsSpectroscopic Binary
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Invisible Companion
Black Hole Neutron Star Brown Dwarf Planet
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Spectrum Binary
Spectroscopic Binary
B5 K2
Hot Cool
What is required? Both Bright Different
Temperature
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Spectroscopic Binary
Velocity
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Eclipsing Binary
Light Curve
magnitude
Time
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Eclipsing Binary
magnitude
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Eclipsing Binary
magnitude
29
Eclipsing Binary
magnitude
30
Eclipsing Binary
magnitude
31
Eclipsing Binary
magnitude
32
Eclipsing Binary
magnitude
33
Eclipsing Binary
magnitude
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Eclipsing Binary
magnitude
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Eclipsing Binary
magnitude
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Eclipsing Binary
magnitude
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Eclipsing Binary
What is required? Both Bright Inclination 90
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Spectroscopic Binary
v v sin i
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Star Masses
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Eclipsing Binary
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Eclipsing Binary
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Eclipsing Binary
magnitude
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Eclipsing Binary
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Eclipsing Binary
magnitude
45
Star Sizes
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Star Sizes
Surface Area 4 p R2 Energy s T4 Luminosity
4 p R2 s T4
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Secondary Primary
48
Surface Brightness
49
Surface Brightness
50
Photosphere
51
Limb Darkening
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With Limb Darkening
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Surface Brightness
54
Star Spots
Hot Spots