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Extrasolar planets
Telluric planets
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Jovian Planets
Giant gaseous planets
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Solar system
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Giordano Bruno (Nola 1548 – Roma 1600)
«..l’infinito, universo e mondi innumerabili.»
«…un Sole Nero inghiottirà nello spazio il sole, la luna, e tutti pianeti che ruotano intorno al sole"
"Ad un corpo di dimensione infinita non può essere attribuito né un centro né un confine”
"L'uomo viaggerà nel cosmo e dal cosmo apprenderà il giorno della sua fine”
(De l'Infinito Universo et Mondi)
“…. le stelle sono infinite e sono soli lontanissimi attorno ai quali girano pianeti e alcuni di questi mondi sono abitati da esseri
intelligenti.”
Extrasolar planets (up to October 2014)
900
800
Number of planets
700
600
500
400
300
200
100
0
1998
2000
2002
2004
2006
2008
Year of discovery
2010
2012
2014
Planets in the dwarf star Gliese 581
Distance: 22 light years
Planets in the dwarf star Gliese 581
Extrasolar planet M1207b
Distance: 52 pc
3-20 times the mass of Jupiter
Distance from the star: 7.8 distance Jupiter - Sun
Direct detection
Two main difficulties :
1 – A tiny angular separation
2 – A huge contrast in luminosity
Sun – Jupiter at 4 light years = 4 arcsec
Sun – Jupiter at 100 light years = 0.15 arcsec
Sun – Earth at 100 light years = 0.03 arcsec
Sun – Earth at 100 parsec = 0.01 arcsec
The star is up to 10 billion
times brighter than the planet
The star is up to 10 billion
times brighter than the planet
A solution:
the method used by Le Verrier for the discovery of Neptune:
the gravitational perturbation induced by the planet
Gravitational perturbation
induced by Jupiter on the Sun
Period : 11.9 years
Distance : 5.2 AU
Velocity : 13 km/s
Period : 11.9 years
Distance : 0.005 AU
Velocity : 12 m/s
Jupiter orbit
C.M.
Solar motion
Center of mass
Dynamical
effects
• Astrometry
• Radial velocity
λ/δλ=100000 —> 3 km/s not enough !
Jupiter - Sun ! Amplitude = 12.5 m/s Period = 11.9 years
Earth - Sun ! Amplitude = 0.1 m/s Period = 1 year
Sensitive to short periods and more massive planets !
Gravitational microlensing
32 candidates up to now
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OGLE 2005-BLG-071Lb
~ 2.7 MJ planet
at ~ 2.2 / 3.7 AU
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Occultation or transit
Evaporation of Hot-Jupiters
Eclipse 4/01/2011 & ISS
Crédit: Thierry Legault
Transit photometry
star
planet
Brightness
Brillance
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Time
Transit probability
Edge-on orbit
(i=90o)
Face-on orbit
(i=0o)
The first transiting planet: Osiris
French mission COROT
COROT-7
NASA mission Kepler
Kepler-10b
Period: 0.84 days
Mass: 4.5 ME
Radius:1.42 RE
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Infrared light curve of HD189733A+b
September 29, 2014
1822 planets
1137 planetary systems
467 multiple planet systems
574 by radial velocity
1147 transiting
32 by microlensing
51 by direct imaging
Extrapolation: several hundreds million of Jovian extrasolar planets in
the Milky Way with periods of 5 or fewer days
Sizes of planets (February 2014)
800
Number of planets
600
400
200
0
Jupiter size
Neptune size
Super-Earth size
Earth size
Present: atmospheres
Future: bio signatures
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