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Extra Solar Planets. Geoff Bower. Radial Velocity Detection of Exoplanets. Exoplanet Statistics from Radial Velocity Variations. Transits. HD 209458 Henry et al 1999. Requirements for Transit Detection of Earth. Photometric sensitivity ~ 10^-5 Nstars >> 10^3 Time resolution ~ hours
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Extra Solar Planets Geoff Bower The Transient Universe: AY 250 Spring 2007
Radial Velocity Detection of Exoplanets The Transient Universe: AY 250 Spring 2007
Exoplanet Statistics from Radial Velocity Variations The Transient Universe: AY 250 Spring 2007
Transits HD 209458 Henry et al 1999 The Transient Universe: AY 250 Spring 2007
Requirements for Transit Detection of Earth • Photometric sensitivity ~ 10^-5 • Nstars >> 10^3 • Time resolution ~ hours • Duration ~ years • Continuous viewing The Transient Universe: AY 250 Spring 2007
TrESTransiting Extrasolar Planet Search • 3 x 10 cm telescopes • 6 x 6 deg FOV • V< 16 mag • 0.005 mag in 10 minutes The Transient Universe: AY 250 Spring 2007
TrES-2 Planet in Kepler Field T=2.5 days M=1.3 MJupR=1.2 MJup O’Donovan et al 2006 The Transient Universe: AY 250 Spring 2007
All Transiting Planets Charbonneau et al 2006 The Transient Universe: AY 250 Spring 2007
TreS-1 HD 209458 Star spot causes bump The Transient Universe: AY 250 Spring 2007
Scintillation Noise < 1sec TrES Dunham et al 2004 Dravins et al 1997 The Transient Universe: AY 250 Spring 2007
Kepler The Transient Universe: AY 250 Spring 2007
Kepler Observing Program • 4 years • Continuous observing • 100 square degrees • 1.4m mirror/0.95 m corrector • 2” pixels • 42 x 1024 x 2200 pixels • Photometry for 100,00 stars The Transient Universe: AY 250 Spring 2007
Photometry for 100,000 Stars • Subset of pixels selected from photometry • Integrated for 15 minutes • Smaller subset with 1 minute integrations • 10^7 measurements/day x ~10-100 pixels/star • GB/day The Transient Universe: AY 250 Spring 2007
Poisson Noise ~ 1/sqrt(Nphotons) • Poisson noise sets mirror size • Stellar variability is the big unknown and factor to be controlled The Transient Universe: AY 250 Spring 2007
450,000 stars brighter than 15th mag The Transient Universe: AY 250 Spring 2007 Basri et al 2005
Most Stars Are Inactive The Transient Universe: AY 250 Spring 2007
Solar Variability The Transient Universe: AY 250 Spring 2007
Hall et al 2007 The Transient Universe: AY 250 Spring 2007
Stellar Variability The Transient Universe: AY 250 Spring 2007
Variability Limits on Planet Size The Transient Universe: AY 250 Spring 2007
Simulated Transit Matched filter search The Transient Universe: AY 250 Spring 2007
Semi-major axis 1500 Earth mass planets detected in first year 4500 in four years Assuming 3 terrestrial planets/star The Transient Universe: AY 250 Spring 2007
Planet Detection Validation • 7 sigma detection (total) in >=4 transits • Period constant to 10 ppm from at least 3 transits • Duration, depth, shape consistent • Star centroid the same in and out of transit • Reject background eclipsing star • Radial velocity follow-up consistent • High resolution imaging The Transient Universe: AY 250 Spring 2007