The Detection of Extrasolar Planets

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The Detection ofExtrasolar Planets

• Dr. Brooke P. Skelton

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GRAVITY
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Our Solar System
By Calvin J. Hamilton http//www.solarviews.com/c
ap/misc/ss.htm
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Our Solar System, seen from 4 billion miles
Images taken by Voyager 1 on February 14, 1990
Note 4 billion miles 43 AU 0.0002 pc
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Formation of a Star
From Pasachoff, Astronomy From the Earth to the
Universe, 4th Edition
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Proplyds in Orion Nebula
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Detecting Extrasolar Planets

• Astrometry

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Newtons Law of Gravity

• G M1 M2

F
R2
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Astrometry
http//www.hao.ucar.edu/public/research/stare/sear
ch.html
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Detecting Extrasolar Planets

• Astrometry

• Pulsar Timing Measurements

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Pulsar Timing Variations
http//www.astro.psu.edu/users/alex/pulsar_planets
_text.html
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Detecting Extrasolar Planets

• Astrometry

• Pulsar Timing Measurements

• Radial Velocity Measurements

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(No Transcript)
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Radial Velocity Variations
http//cfa-www.harvard.edu/afoe/orbits/rhoCrB-orbi
t.mpg
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Newtons Law of Gravity

• G M1 M2

F
R2
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Keplers Laws

• The orbit of a planet is an ellipse with the Sun
  at one focus.

• A planet travels fastest when closest to the Sun
  and slowest when farthest.

• There is a relationship between the orbital
  period of a planet and its average distance from
  the Sun that depends on the mass of the central
  body.

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Deriving Planetary Masses

• Observe period and amplitude of stars motion.

2. Derive size of orbit using Keplers 3rd Law.
http//exoplanets.org/graphics/kepslaw.gif
P period of orbit K amplitude V sin i i
inclination of orbit with respect to
observer
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Deriving Planetary Masses

• Observe period and amplitude of stars motion.

2. Derive size of orbit using Keplers 3rd Law.
3. Calculate velocity of planet using Newtons
2nd Law and Law of Gravity.
http//exoplanets.org/graphics/kepslaw.gif
P period of orbit K amplitude V sin i i
inclination of orbit with respect to
observer
F ma
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Deriving Planetary Masses

• Observe period and amplitude of stars motion.

2. Derive size of orbit using Keplers 3rd Law.
3. Calculate velocity of planet using Newtons
2nd Law and Law of Gravity.
http//exoplanets.org/graphics/kepslaw.gif
P period of orbit K amplitude V sin i i
inclination of orbit with respect to
observer
20
Deriving Planetary Masses

• Observe period and amplitude of stars motion.

2. Derive size of orbit using Keplers 3rd Law.
3. Calculate velocity of planet using Newtons
2nd Law and Law of Gravity.
http//exoplanets.org/graphics/kepslaw.gif
P period of orbit K amplitude V sin i i
inclination of orbit with respect to
observer
4. Estimate mass of planet with momentum
conservation.
MplVpl MV
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Deriving Planetary Masses

• Observe period and amplitude of stars motion.

2. Derive size of orbit using Keplers 3rd Law.
3. Calculate velocity of planet using Newtons
2nd Law and Law of Gravity.
http//exoplanets.org/graphics/kepslaw.gif
P period of orbit K amplitude V sin i i
inclination of orbit with respect to
observer
4. Estimate mass of planet with momentum
conservation.
Mpl sin i MK / Vpl
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Detecting Extrasolar Planets

• Astrometry

• Pulsar Timing Measurements

• Radial Velocity Measurements

• Microlensing

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Microlensing
http//www.exoplaneten.de/MACHO-98-BLG-35/english.
html
http//sirrah.troja.mff.cuni.cz/mira/astronomicky
_kurz_hphk/Exoplanety/037microlensing_16-5.png
http//www.nd.edu/srhie/MPS/
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Detecting Extrasolar Planets

• Astrometry

• Pulsar Timing Measurements

• Radial Velocity Measurements

• Microlensing

• Direct Imaging

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Imaging in the near-infrared
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Detecting Extrasolar Planets

• Astrometry

• Pulsar Timing Measurements

• Radial Velocity Measurements

• Microlensing

• Direct Imaging

• Imaging of Planetary Transits and Eclipses

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Seeing extrasolar planets
Eclipse of planet by star
Transit of planet across star
http//www.hao.ucar.edu/public/research/stare/hd20
9458.html
http//www.hao.ucar.edu/public/research/stare/tres
1_2.html
http//www.hao.ucar.edu/public/research/stare/curv
es.html
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So what do we find?
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Detected Extrasolar Planets

• Astrometry 0 candidates

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The 61 Cygni system
http//www.dibonsmith.com/cyg_61.gif
Photo by Francois du Toit http//home.intekom.com/
franlet/astronomyPAGE108.htm
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Detected Extrasolar Planets

• Astrometry 0 candidates

• Pulsar Timing 4 planets in 2 systems

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PSR B125712
http//www.uranos.eu.org/biogr/wolsze.html
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Detected Extrasolar Planets

• Astrometry 0 candidates

• Pulsar Timing 4 planets in 2 systems

• Direct Imaging 3 very large planets

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GQ Lup and AB Pic
M 13.5 MJ at R 275 AU
M 21.5 MJ at R 103 AU
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Detected Extrasolar Planets

• Astrometry 0 candidates

• Pulsar Timing 4 planets in 2 systems

• Microlensing 3 planets 2 Jupiter-like and one
  Earth-like

• Direct Imaging 3 very large planets

• Imaging of Transits 1 Jupiter-like planet

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OGLE 2005-BLG-390L
http//planet.iap.fr/PublicCurves/OB05390p.gif
Mass 5.5 ME at R 2.6 AU
http//planet.iap.fr/OB05390.news.html
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Detected Extrasolar Planets

• Astrometry 0 candidates

• Pulsar Timing 4 planets in 2 systems

• Radial Velocity Measurements 171 planets in 147
  planetary systems most quite large (Saturn- and
  Jupiter-like)

• Microlensing 3 planets 2 Jupiter-like and one
  Earth-like

• Direct Imaging 3 very large planets

• Imaging of Transits 1 Jupiter-like planet

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51 Pegasi
http//exoplanets.org/esp/51peg/51peg.shtml
http//exoplanets.org/esp/51peg/51peg.shtml
http//www.exoplaneten.de/51peg/english.html
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www.physics.sfsu.edu/gmarcy/planetsearch/7504/750
4.html
www.exoplanets.org
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A Very Eccentric Planet
http//cfa-www.harvard.edu/afoe/orbits/16CygB-orbi
t.mpg
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Masses and Orbits of Extrasolar Planets
www.exoplanets.org
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A Planetary System
http//exoplanets.org/esp/upsandb/upsandb.shtml
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Upsilon Andromedae
http//antwrp.gsfc.nasa.gov/apod/ap990422.html
http//exoplanets.org/esp/upsandb/upsandb.shtml
http//www.exoplaneten.de/upsand/english.html
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F ma
MplVpl MV
Mpl sin i MK / Vpl
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Newtons Form of Keplers Third Law

• 4p2

a3
P2
G(m1 m2)
P period of orbit a semimajor axis of
orbit m1, m2 masses of Sun and planet
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A Sample of Observed Planets
Our Solar System
First known extrasolar planet, 51 Pegasi
First known extrasolar system, Upsilon Andromedae