Real Life Death Stars: Measuring Rocks on Alien Planets by Tearing Them Apart

Outreach talk, 40 min. January 2016: Astronomy Days, North Carolina Museum of Natural Sciences, Raleigh, NC, USA.

Transcript

1. Real-Life Death Stars:
   Measuring Rocks on
   Alien Planets by
   Tearing Them Apart
   JJ Hermes
   Hubble Fellow
   University of North Carolina at Chapel Hill
   jjhermes.web.unc.edu
   

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2. Kitt Peak National Observatory, Arizona
   

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3. My History: The University of Texas at Austin
   • Undergrad in
   Physics &
   Astronomy,
   2002-2007
   • Ph.D. in
   Astronomy,
   2008-2013
   • I have spent
   >220 nights at
   McDonald
   Observatory
   

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4. My History: The University of Warwick
   • I did my first Postdoctoral Research Fellowship in England
   – There I learned to include a ‘u’ in words like colour
   • Astronomers tend to have postdoc appointments for 2-7(!) years before
   settling in at a faculty job teaching at a university
   William Herschel Telescope, Canary Islands, Spain
   

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5. My History: The University of North Carolina
   • Currently I am a Hubble Fellow at the University of North Carolina at Chapel
   Hill, another postdoctoral research job
   

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6. V = 13.3 mag Star Wars: A New Hope © Disney
   

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7. We Have Found Thousands of Planets
   Outside Our Solar System
   

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8. “So What Might Alien
   Life Look Like?”
   “The Search for Life Beyond Earth…”
   

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9. This is still the stuff of science fiction
   JD Hancock
   

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10. “What Are Rocks Like
    on Alien Worlds?”
    Alien World = Extrasolar Planets (Planets
    Outside Our Solar System)
    

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11. They are mostly composed of:
    Iron, Oxygen, Silicon, Magnesium … and Water!
    Alien Worlds are Just
    Like Rocks on Earth
    Earth
    “Alien Rocks”
    

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12. “So How Do We Know
    Anything About Alien
    Rocks?”
    

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13. Light Is the Only Way Know
    About Anything Outside Our
    Solar System
    

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14. You Need to Know Two Things:
    1. Each Atom
    Has Its Own
    Fingerprint
    2. Very Old
    Stars are a
    Blank Canvas
    Henry Bloomfield
    

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15. Each Atom Has Its Own Fingerprint
    Passing SunlightThrough a Prism:
    Each Line is from an ELEMENT!
    Boston University
    

    View Slide

16. La-Lu
    57-71
    Ac-Lr
    89-103
    Tc
    Lr
    Pm
    Np Pu Am Cm Bk Cf Es Fm Md No
    Bh
    Rf Db Sg Hs Mt
    1
    2
    3
    4
    5
    6
    7
    1.0079
    1 4.0026
    2
    20.180
    10
    14.007
    7
    39.948
    18
    35.453
    17
    18.998
    9
    15.999
    8
    83.798
    36
    131.29
    54
    (222)
    86
    12.011
    6
    C
    10.811
    B
    5
    26.982
    Al
    13 28.086
    Si
    14 30.974
    P
    15 32.065
    S
    16
    6.941
    Li
    3 9.0122
    Be
    4
    22.990
    Na
    11 24.305
    Mg
    12
    39.098
    K
    19 40.078
    Ca
    20 44.956
    Sc
    21 47.867
    Ti
    22 50.942
    V
    23 51.996
    Cr
    24 54.938
    Mn
    25 55.845
    Fe
    26 58.933
    Co
    27 58.693
    Ni
    28 63.546
    Cu
    29 65.38
    Zn
    30 69.723
    Ga
    31 72.64
    Ge
    32 74.922
    As
    33 78.96
    Se
    34 79.904
    35
    85.468
    Rb
    37 87.62
    Sr
    38 88.906
    Y
    39 91.224
    Zr
    40 92.906
    Nb
    41 95.96
    Mo
    42
    132.91
    Cs
    55 137.33
    Ba
    56
    138.91
    La
    57
    178.49
    Hf
    72 180.95
    Ta
    73 183.84
    W
    74
    (223)
    Fr
    87 (226)
    Ra
    88
    (227)
    Ac
    89
    (98)
    43 126.90
    I
    53
    101.07
    Ru
    44 102.91
    Rh
    45 106.42
    Pd
    46 107.87
    Ag
    47 112.41
    Cd
    48
    186.21
    Re
    75 190.23
    Os
    76 192.22
    Ir
    77 195.08
    Pt
    78 196.97
    Au
    79 200.59
    Hg
    80 204.38
    Tl
    81 207.2
    Pb
    82 208.98
    Bi
    83 (209)
    Po
    84 (210)
    At
    85
    114.82
    In
    49 118.71
    Sn
    50 121.76
    Sb
    51 127.60
    Te
    52
    H He
    Ne
    N
    Ar
    Cl
    F
    O
    Kr
    Xe
    Rn
    Br
    IA
    IIA
    IIIB IVB VB VIB VIIB IB IIB
    IVA VA VIA VIIA
    VIIIB
    VIIIA
    1
    5
    4
    2
    3
    13 14 15 16 17
    18
    6 7 8 9 10 11 12
    IIIA
    174.97
    Lu
    71
    140.12
    Ce
    58
    232.04
    Th
    90 231.04
    Pa
    91 238.03
    U
    92
    140.91
    Pr
    59 144.24
    Nd
    60
    (262)
    103
    (145)
    61
    (237)
    93 (244)
    94 (243)
    95 (247)
    96 (247)
    97 (251)
    98 (252)
    99 (257)
    100 (258)
    101 (259)
    102
    150.36
    Sm
    62 151.96
    Eu
    63 157.25
    Gd
    64 158.93
    Tb
    65 162.50
    Dy
    66 164.93
    Ho
    67 167.26
    Er
    68 168.93
    Tm
    69 173.05
    Yb
    70
    (2 )
    72
    107
    (26 )
    7
    104 (26 )
    8
    105 (2 )
    71
    106 (277)
    108 (2 )
    76
    109 (2 1)
    8
    Ds
    110 (2 )
    80
    Rg
    111
    10.811
    B
    5
    13 IIIA
    (2 )
    85
    Cn
    112 118
    113 114 115 116 117 ( )
    . . .
    ( )
    . . . (2 )
    87 ( )
    . . . (2 )
    91 ( )
    . . .
    Uut Fl Uup Lv Uus Uuo
    Copyright Eni G
    © 2012 eneralić
    HYDROGEN HELIUM
    NEON
    NITROGEN
    ARGON
    CHLORINE
    FLUORINE
    OXYGEN
    KRYPTON
    XENON
    RADON
    CARBON
    BORON
    ALUMINIUM SILICON PHOSPHORUS SULPHUR
    LITHIUM BERYLLIUM
    SODIUM MAGNESIUM
    POTASSIUM CALCIUM SCANDIUM TITANIUM VANADIUM CHROMIUM MANGANESE COBALT NICKEL COPPER ZINC GALLIUM GERMANIUM ARSENIC SELENIUM BROMINE
    RUBIDIUM STRONTIUM YTTRIUM ZIRCONIUM NIOBIUM MOLYBDENUM
    CAESIUM BARIUM
    LANTHANUM
    HAFNIUM TANTALUM TUNGSTEN
    FRANCIUM RADIUM
    ACTINIUM
    TECHNETIUM IODINE
    RUTHENIUM RHODIUM PALLADIUM SILVER CADMIUM
    RHENIUM OSMIUM IRIDIUM PLATINUM GOLD THALLIUM LEAD BISMUTH POLONIUM ASTATINE
    INDIUM TIN ANTIMONY TELLURIUM
    PERIOD
    GROUP
    IRON
    MERCURY
    LUTETIUM
    CERIUM
    THORIUM PROTACTINIUM URANIUM
    PRASEODYMIUM NEODYMIUM
    LAWRENCIUM
    PROMETHIUM
    NEPTUNIUM PLUTONIUM AMERICIUM CURIUM BERKELIUM CALIFORNIUM EINSTEINIUM FERMIUM MENDELEVIUM NOBELIUM
    SAMARIUM EUROPIUM GADOLINIUM TERBIUM DYSPROSIUM HOLMIUM ERBIUM THULIUM YTTERBIUM
    BOHRIUM
    RUTHERFORDIUM DUBNIUM SEABORGIUM HASSIUM MEITNERIUM
    BORON
    ATOMIC NUMBER
    ELEMENT NAME
    SYMBOL
    RELATIVE ATOMIC MASS (1)
    GROUP NUMBERS
    CHEMICAL ABSTRACT SERVICE
    (1986)
    GROUP NUMBERS
    IUPAC RECOMMENDATION
    (1985)
    Lanthanide
    Actinide
    ROENTGENIUM
    PERIODIC TABLE OF THE ELEMENTS
    LANTHANIDE
    ACTINIDE
    DARMSTADTIUM
    h .com
    ttp://www.periodni
    COPERNICIUM UNUNTRIUM FLEROVIUM UNUNPENTIUM LIVERMORIUM UNUNSEPTIUM UNUNOCTIUM
    Relative atomic masses are expressed with
    five significant figures. For elements that have
    no stable nuclides, the value enclosed in
    brackets indicates the mass number of the
    longest-lived isotope of the element. However
    three such elements (Th, Pa and U) do have a
    characteristic terrestrial isotopic composition,
    and for these an atomic weight is tabulated.
    (1) Pure Appl. Chem., , No. , (200 )
    81 11 2131-2156 9
    Hydrogen
    

    View Slide

17. La-Lu
    57-71
    Ac-Lr
    89-103
    Tc
    Lr
    Pm
    Np Pu Am Cm Bk Cf Es Fm Md No
    Bh
    Rf Db Sg Hs Mt
    1
    2
    3
    4
    5
    6
    7
    1.0079
    1 4.0026
    2
    20.180
    10
    14.007
    7
    39.948
    18
    35.453
    17
    18.998
    9
    15.999
    8
    83.798
    36
    131.29
    54
    (222)
    86
    12.011
    6
    C
    10.811
    B
    5
    26.982
    Al
    13 28.086
    Si
    14 30.974
    P
    15 32.065
    S
    16
    6.941
    Li
    3 9.0122
    Be
    4
    22.990
    Na
    11 24.305
    Mg
    12
    39.098
    K
    19 40.078
    Ca
    20 44.956
    Sc
    21 47.867
    Ti
    22 50.942
    V
    23 51.996
    Cr
    24 54.938
    Mn
    25 55.845
    Fe
    26 58.933
    Co
    27 58.693
    Ni
    28 63.546
    Cu
    29 65.38
    Zn
    30 69.723
    Ga
    31 72.64
    Ge
    32 74.922
    As
    33 78.96
    Se
    34 79.904
    35
    85.468
    Rb
    37 87.62
    Sr
    38 88.906
    Y
    39 91.224
    Zr
    40 92.906
    Nb
    41 95.96
    Mo
    42
    132.91
    Cs
    55 137.33
    Ba
    56
    138.91
    La
    57
    178.49
    Hf
    72 180.95
    Ta
    73 183.84
    W
    74
    (223)
    Fr
    87 (226)
    Ra
    88
    (227)
    Ac
    89
    (98)
    43 126.90
    I
    53
    101.07
    Ru
    44 102.91
    Rh
    45 106.42
    Pd
    46 107.87
    Ag
    47 112.41
    Cd
    48
    186.21
    Re
    75 190.23
    Os
    76 192.22
    Ir
    77 195.08
    Pt
    78 196.97
    Au
    79 200.59
    Hg
    80 204.38
    Tl
    81 207.2
    Pb
    82 208.98
    Bi
    83 (209)
    Po
    84 (210)
    At
    85
    114.82
    In
    49 118.71
    Sn
    50 121.76
    Sb
    51 127.60
    Te
    52
    H He
    Ne
    N
    Ar
    Cl
    F
    O
    Kr
    Xe
    Rn
    Br
    IA
    IIA
    IIIB IVB VB VIB VIIB IB IIB
    IVA VA VIA VIIA
    VIIIB
    VIIIA
    1
    5
    4
    2
    3
    13 14 15 16 17
    18
    6 7 8 9 10 11 12
    IIIA
    174.97
    Lu
    71
    140.12
    Ce
    58
    232.04
    Th
    90 231.04
    Pa
    91 238.03
    U
    92
    140.91
    Pr
    59 144.24
    Nd
    60
    (262)
    103
    (145)
    61
    (237)
    93 (244)
    94 (243)
    95 (247)
    96 (247)
    97 (251)
    98 (252)
    99 (257)
    100 (258)
    101 (259)
    102
    150.36
    Sm
    62 151.96
    Eu
    63 157.25
    Gd
    64 158.93
    Tb
    65 162.50
    Dy
    66 164.93
    Ho
    67 167.26
    Er
    68 168.93
    Tm
    69 173.05
    Yb
    70
    (2 )
    72
    107
    (26 )
    7
    104 (26 )
    8
    105 (2 )
    71
    106 (277)
    108 (2 )
    76
    109 (2 1)
    8
    Ds
    110 (2 )
    80
    Rg
    111
    10.811
    B
    5
    13 IIIA
    (2 )
    85
    Cn
    112 118
    113 114 115 116 117 ( )
    . . .
    ( )
    . . . (2 )
    87 ( )
    . . . (2 )
    91 ( )
    . . .
    Uut Fl Uup Lv Uus Uuo
    Copyright Eni G
    © 2012 eneralić
    HYDROGEN HELIUM
    NEON
    NITROGEN
    ARGON
    CHLORINE
    FLUORINE
    OXYGEN
    KRYPTON
    XENON
    RADON
    CARBON
    BORON
    ALUMINIUM SILICON PHOSPHORUS SULPHUR
    LITHIUM BERYLLIUM
    SODIUM MAGNESIUM
    POTASSIUM CALCIUM SCANDIUM TITANIUM VANADIUM CHROMIUM MANGANESE COBALT NICKEL COPPER ZINC GALLIUM GERMANIUM ARSENIC SELENIUM BROMINE
    RUBIDIUM STRONTIUM YTTRIUM ZIRCONIUM NIOBIUM MOLYBDENUM
    CAESIUM BARIUM
    LANTHANUM
    HAFNIUM TANTALUM TUNGSTEN
    FRANCIUM RADIUM
    ACTINIUM
    TECHNETIUM IODINE
    RUTHENIUM RHODIUM PALLADIUM SILVER CADMIUM
    RHENIUM OSMIUM IRIDIUM PLATINUM GOLD THALLIUM LEAD BISMUTH POLONIUM ASTATINE
    INDIUM TIN ANTIMONY TELLURIUM
    PERIOD
    GROUP
    IRON
    MERCURY
    LUTETIUM
    CERIUM
    THORIUM PROTACTINIUM URANIUM
    PRASEODYMIUM NEODYMIUM
    LAWRENCIUM
    PROMETHIUM
    NEPTUNIUM PLUTONIUM AMERICIUM CURIUM BERKELIUM CALIFORNIUM EINSTEINIUM FERMIUM MENDELEVIUM NOBELIUM
    SAMARIUM EUROPIUM GADOLINIUM TERBIUM DYSPROSIUM HOLMIUM ERBIUM THULIUM YTTERBIUM
    BOHRIUM
    RUTHERFORDIUM DUBNIUM SEABORGIUM HASSIUM MEITNERIUM
    BORON
    ATOMIC NUMBER
    ELEMENT NAME
    SYMBOL
    RELATIVE ATOMIC MASS (1)
    GROUP NUMBERS
    CHEMICAL ABSTRACT SERVICE
    (1986)
    GROUP NUMBERS
    IUPAC RECOMMENDATION
    (1985)
    Lanthanide
    Actinide
    ROENTGENIUM
    PERIODIC TABLE OF THE ELEMENTS
    LANTHANIDE
    ACTINIDE
    DARMSTADTIUM
    h .com
    ttp://www.periodni
    COPERNICIUM UNUNTRIUM FLEROVIUM UNUNPENTIUM LIVERMORIUM UNUNSEPTIUM UNUNOCTIUM
    Relative atomic masses are expressed with
    five significant figures. For elements that have
    no stable nuclides, the value enclosed in
    brackets indicates the mass number of the
    longest-lived isotope of the element. However
    three such elements (Th, Pa and U) do have a
    characteristic terrestrial isotopic composition,
    and for these an atomic weight is tabulated.
    (1) Pure Appl. Chem., , No. , (200 )
    81 11 2131-2156 9
    Helium
    

    View Slide

18. La-Lu
    57-71
    Ac-Lr
    89-103
    Tc
    Lr
    Pm
    Np Pu Am Cm Bk Cf Es Fm Md No
    Bh
    Rf Db Sg Hs Mt
    1
    2
    3
    4
    5
    6
    7
    1.0079
    1 4.0026
    2
    20.180
    10
    14.007
    7
    39.948
    18
    35.453
    17
    18.998
    9
    15.999
    8
    83.798
    36
    131.29
    54
    (222)
    86
    12.011
    6
    C
    10.811
    B
    5
    26.982
    Al
    13 28.086
    Si
    14 30.974
    P
    15 32.065
    S
    16
    6.941
    Li
    3 9.0122
    Be
    4
    22.990
    Na
    11 24.305
    Mg
    12
    39.098
    K
    19 40.078
    Ca
    20 44.956
    Sc
    21 47.867
    Ti
    22 50.942
    V
    23 51.996
    Cr
    24 54.938
    Mn
    25 55.845
    Fe
    26 58.933
    Co
    27 58.693
    Ni
    28 63.546
    Cu
    29 65.38
    Zn
    30 69.723
    Ga
    31 72.64
    Ge
    32 74.922
    As
    33 78.96
    Se
    34 79.904
    35
    85.468
    Rb
    37 87.62
    Sr
    38 88.906
    Y
    39 91.224
    Zr
    40 92.906
    Nb
    41 95.96
    Mo
    42
    132.91
    Cs
    55 137.33
    Ba
    56
    138.91
    La
    57
    178.49
    Hf
    72 180.95
    Ta
    73 183.84
    W
    74
    (223)
    Fr
    87 (226)
    Ra
    88
    (227)
    Ac
    89
    (98)
    43 126.90
    I
    53
    101.07
    Ru
    44 102.91
    Rh
    45 106.42
    Pd
    46 107.87
    Ag
    47 112.41
    Cd
    48
    186.21
    Re
    75 190.23
    Os
    76 192.22
    Ir
    77 195.08
    Pt
    78 196.97
    Au
    79 200.59
    Hg
    80 204.38
    Tl
    81 207.2
    Pb
    82 208.98
    Bi
    83 (209)
    Po
    84 (210)
    At
    85
    114.82
    In
    49 118.71
    Sn
    50 121.76
    Sb
    51 127.60
    Te
    52
    H He
    Ne
    N
    Ar
    Cl
    F
    O
    Kr
    Xe
    Rn
    Br
    IA
    IIA
    IIIB IVB VB VIB VIIB IB IIB
    IVA VA VIA VIIA
    VIIIB
    VIIIA
    1
    5
    4
    2
    3
    13 14 15 16 17
    18
    6 7 8 9 10 11 12
    IIIA
    174.97
    Lu
    71
    140.12
    Ce
    58
    232.04
    Th
    90 231.04
    Pa
    91 238.03
    U
    92
    140.91
    Pr
    59 144.24
    Nd
    60
    (262)
    103
    (145)
    61
    (237)
    93 (244)
    94 (243)
    95 (247)
    96 (247)
    97 (251)
    98 (252)
    99 (257)
    100 (258)
    101 (259)
    102
    150.36
    Sm
    62 151.96
    Eu
    63 157.25
    Gd
    64 158.93
    Tb
    65 162.50
    Dy
    66 164.93
    Ho
    67 167.26
    Er
    68 168.93
    Tm
    69 173.05
    Yb
    70
    (2 )
    72
    107
    (26 )
    7
    104 (26 )
    8
    105 (2 )
    71
    106 (277)
    108 (2 )
    76
    109 (2 1)
    8
    Ds
    110 (2 )
    80
    Rg
    111
    10.811
    B
    5
    13 IIIA
    (2 )
    85
    Cn
    112 118
    113 114 115 116 117 ( )
    . . .
    ( )
    . . . (2 )
    87 ( )
    . . . (2 )
    91 ( )
    . . .
    Uut Fl Uup Lv Uus Uuo
    Copyright Eni G
    © 2012 eneralić
    HYDROGEN HELIUM
    NEON
    NITROGEN
    ARGON
    CHLORINE
    FLUORINE
    OXYGEN
    KRYPTON
    XENON
    RADON
    CARBON
    BORON
    ALUMINIUM SILICON PHOSPHORUS SULPHUR
    LITHIUM BERYLLIUM
    SODIUM MAGNESIUM
    POTASSIUM CALCIUM SCANDIUM TITANIUM VANADIUM CHROMIUM MANGANESE COBALT NICKEL COPPER ZINC GALLIUM GERMANIUM ARSENIC SELENIUM BROMINE
    RUBIDIUM STRONTIUM YTTRIUM ZIRCONIUM NIOBIUM MOLYBDENUM
    CAESIUM BARIUM
    LANTHANUM
    HAFNIUM TANTALUM TUNGSTEN
    FRANCIUM RADIUM
    ACTINIUM
    TECHNETIUM IODINE
    RUTHENIUM RHODIUM PALLADIUM SILVER CADMIUM
    RHENIUM OSMIUM IRIDIUM PLATINUM GOLD THALLIUM LEAD BISMUTH POLONIUM ASTATINE
    INDIUM TIN ANTIMONY TELLURIUM
    PERIOD
    GROUP
    IRON
    MERCURY
    LUTETIUM
    CERIUM
    THORIUM PROTACTINIUM URANIUM
    PRASEODYMIUM NEODYMIUM
    LAWRENCIUM
    PROMETHIUM
    NEPTUNIUM PLUTONIUM AMERICIUM CURIUM BERKELIUM CALIFORNIUM EINSTEINIUM FERMIUM MENDELEVIUM NOBELIUM
    SAMARIUM EUROPIUM GADOLINIUM TERBIUM DYSPROSIUM HOLMIUM ERBIUM THULIUM YTTERBIUM
    BOHRIUM
    RUTHERFORDIUM DUBNIUM SEABORGIUM HASSIUM MEITNERIUM
    BORON
    ATOMIC NUMBER
    ELEMENT NAME
    SYMBOL
    RELATIVE ATOMIC MASS (1)
    GROUP NUMBERS
    CHEMICAL ABSTRACT SERVICE
    (1986)
    GROUP NUMBERS
    IUPAC RECOMMENDATION
    (1985)
    Lanthanide
    Actinide
    ROENTGENIUM
    PERIODIC TABLE OF THE ELEMENTS
    LANTHANIDE
    ACTINIDE
    DARMSTADTIUM
    h .com
    ttp://www.periodni
    COPERNICIUM UNUNTRIUM FLEROVIUM UNUNPENTIUM LIVERMORIUM UNUNSEPTIUM UNUNOCTIUM
    Relative atomic masses are expressed with
    five significant figures. For elements that have
    no stable nuclides, the value enclosed in
    brackets indicates the mass number of the
    longest-lived isotope of the element. However
    three such elements (Th, Pa and U) do have a
    characteristic terrestrial isotopic composition,
    and for these an atomic weight is tabulated.
    (1) Pure Appl. Chem., , No. , (200 )
    81 11 2131-2156 9
    Sodium
    

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19. V = 13.3 mag Alwyn Ladell
    

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20. This is Called “Spectroscopy”
    Passing SunlightThrough a Prism:
    This dark line here is from CALCIUM
    Boston University
    

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21. You Need to Know Two Things:
    1. Each Atom
    Has Its Own
    Fingerprint
    2. Very Old
    Stars are a
    Blank Canvas
    Henry Bloomfield
    

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22. But each one contributes less than
    0.000000000000001% of the Sun’s metals
    Comets crash into our
    Sun all the time.
    

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24. All stars like the Sun eventually
    run out of fuel.
    When they do, they lose all their
    envelope and only the core remains:
    a white dwarf star.
    

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27. Sun
    White Dwarf
    (60% Mass of Sun)
    Earth
    (0.0003% Mass of Sun)
    

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28. Under Gravity, Heaviest Elements Sink
    Sharyn Morrow
    A ‘Typical’ White Dwarf
    Carbon/Oxygen Core
    (r = 8500 km)
    Helium Layer
    (260 km)
    Outer Hydrogen Layer
    (30 km)
    

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29. Most White Dwarfs: Only Hydrogen
    

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30. Some White Dwarfs Show Metals
    

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31. Mark Garlick
    

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33. The Abundances
    Resemble Earth
    and Meteorites
    Jay Farihi 2011
    

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34. Earth
    Rocks Falling on
    White Dwarfs
    Iron, Oxygen,
    Silicon,
    Magnesium
    Xu et al. 2014
    

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35. Earth
    Rocks Falling on
    White Dwarfs
    Iron, Oxygen,
    Silicon,
    Magnesium
    Xu et al. 2014
    Mike Jura, UCLA
    

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38. Today
    Boris Gänsicke
    

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39. 5.5 billion years
    from now
    Boris Gänsicke
    

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40. The life cycle of the Sun
    9 billion years
    from now
    Boris Gänsicke
    

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41. 1. Take a solar system. There are
    likely billions in our Galaxy.
    2. As the host star evolves, the
    orbits of planets expand.
    Some may scatter and collide.
    3. Ancient solar systems have
    leftover debris. We can see it if it
    gets close to a white dwarf.
    

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42. Saturn: Familiar Debris Rings
    

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43. White Dwarfs: Debris Rings on Steroids
    

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44. V = 13.3 mag Star Wars: A New Hope © Disney
    

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45. V = 13.3 mag Star Wars: A New Hope © Disney
    

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46. Mark Garlick
    

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47. Mark Garlick
    A. Vanderburg et al. 2015; Gänsicke et al. 2016
    

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48. Mark Garlick
    

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49. We can measure the bulk abundances of
    rocks in extrasolar planetary systems
    

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50. What about water?
    

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51. Mark Garlick
    

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52. Oxygen Excess: Water-Rich Material!
    Rocks = MgO, Al2
    O3
    , SiO2
    ,
    CaO, TiO2
    , Cr2
    O3
    ,
    MnO, FeO, Fe2
    O3
    , ...
    Anything Else = CO2
    , H2
    O
    Farihi et al. 2013;
    Raddi et al. 2015
    Very little Carbon, so excess
    Oxygen likely H2
    O!
    White Dwarf GD 61
    Two specific white dwarfs have
    rocks, maybe worlds, that
    are roughly 25-40% water!
    

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53. Billions of planets likely exist in the Galaxy
    “The Search for Life Beyond Earth…”
    Many of these planets are rocky, like Earth
    Using ancient stars, we can learn that these
    alien rocks are composed of the same
    material as Earth… including water!
    

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54. Sheila Sund
    

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