KEPLER Discovery Mission # 10 William Borucki, PI NASA Ames

2 WB/lct KEY QUESTIONS: Are terrestrial planets common or rare? How many are in the habitable zone? What are their sizes & distances? Dependence on stellar properties

3 WB/lct SCIENTIFIC GOALS Determine the frequency of terrestrial and larger planets in or near the habitable zone of a wide variety of stellar spectral types Determine the distribution of sizes and semi-major axes of these planets Identify additional members of each photometrically discovered planetary system using complementary techniques Determine the distributions of semi-major axis, albedo, size, and density of short-period giant planets Estimate the frequency of planets orbiting multiple star systems Determine the properties of those stars that harbor planetary systems

4 WB/lct KNOWN EXTRASOLAR PLANETS

5 WB/lct DOPPLER VELOCITY MEASURMENTS

6 WB/lct

7

8 Use transit photometry to detect Earth-size planets 0.95 meter aperture provides enough photons Observe for several years to detect the pattern of transits Monitor stars continuously to avoid missing transits Use heliocentric orbit Get statistically valid results by monitoring 100,000 stars Use wide field of view telescope Use a large array of CCD detectors 21 CCD Modules are the Heart of the Kepler Mission MISSION DESIGN KEPLER: A Wide FOV Telescope that Monitors 100,000 Stars for 4 years with Enough Precision to Find Earth-size Planets in the HZ

9 WB/lct REQUIRED SENSITIVITY ∆L/L = area Earth/area Sun = 1/12,000 = 8x10 -5 Require total noise to be <2x10 -5 for 4-sigma detection in 6.5 hours Three sources of noise and their contributions: - Stellar variability:<1x10 -5, typically for the Sun on timescale of ~1/2 day - Shot noise:1.4x10 -5, in 6.5 hr for m v =12 solar-like star and 0.95-meter aperture -Instrument noise: <1x10 -5, including detector dark current, electronics read noise, thermal effects, spacecraft pointing jitter, and shutterless operation. Detector of choice: array of 42–2kx1k CCDs with 27µm pixels and dual readout -Thinned, back-illuminated, anti-reflection coated Limiting bright magnitude of m v =9 and full-well depth of 10 6 e - requires: - Defocus image to 5 pixel square and readout every 3 seconds.

10 WB/lct MEASUREMENT TECHNIQUE Use differential photometry (common mode rejection): - Brightness of each star is re-normalized to the ensemble of thousands of stars in each half of each CCD & readout with a single amplifier; Transits only last several hours: - Long term photometric stability not necessary; Defocus the star image to five pixel square: - Mitigates saturation (10 9 e - /hr) and sensitivity to motion; Control pointing to 3 millipixels (0.01 arc sec); - Star images remain on the same group of pixels, eliminates effects of inter-pixel variations in sensitivity; Operate CCDs near full-well capacity: - Dark current and read-noise effects become negligible; Place the photometer in a heliocentric orbit (SIRTF-like): - Provides for a very stable thermal and stray light environment.

11 WB/lct SCIENCE DRIVER Statistically valid result for abundance of Earth-size planets in habitable zone Expected # of planets found, assuming one planet of a given size & semi-major axis per star and random orientation of orbital planes. # of Planet Detections Orbital Semi-major Axis (AU)

12 WB/lct Stellar Occultations & High- Precision CCD Photometry Timothy Brown, HAO, UCAR Edward Dunham, Lowell Obs. John Geary, SAO Ronald Gilliland, STScI Steve Howell, U. Cal., Riverside Jon M. Jenkins, SETI Institute Doppler Velocity Planet Searches William Cochran, UTexas David Latham, CfA, SAO Geoff Marcy, U. Cal., Berkeley Stellar Variability Gibor Basri, U. Cal., Berkeley Andrea Dupree, CfA, SAO Dmiter Sasselov, CfA, Harvard Theoretical Studies Alan Boss, Carneige Institute Wash. Jack Lissauer, NASA Ames Mission Operations Donald Brownlee, U. of Washington Yoji Kondo, NASA GSGC General Overview John Caldwell, York U. David Morrison, NASA Ames Tobias Owen, Univ. Hawaii Harold Reitsema, Ball Aerospace Co. Jill Tarter, SETI Institute Education and Public Outreach Edna DeVore, SETI Institute Alan Gould, Lawrence Hall of Science William J. Borucki, PI, and David Koch, Deputy PI SCIENCE TEAM

13 WB/lct OPERATIONS ORGANIZATION

14 WB/lct EDUCATIONAL & PUBLIC OUTREACH Lessons, simulations — Website — Information, data Informal New GEMS strand: Space Science “ Finding New Worlds” FOSS Teacher workshops Space Place activities Hands On Universe Planet-finding for high school Kepler-CAM (Underserved/ minority colleges) Multi-media planetarium program (large dome) Interactive planetarium program (small dome) Kepler CD-ROM Exhibit Orrery Transit Model Amateur Astronomers -kit -ephemerides -TransitSearch Broadcast television program STARDATE radio programs Public Outreach Formal

15 WB/lct SCHEDULE & MISSION STATUS Bill Borucki CCD Detectors are arriving from both vendors Optics are on order Preparing for the first major review

16 WB/lct VALIDATION OF DISCOVERIES  Signal to Noise Ratio (SNR) > 7 to rule out statistical fluctuations  Three or more transits to confirm orbital characteristics  Light curve depth, shape, and duration  Image subtraction to identify signals from background stars  Radial velocity Medium resolution to rule out stellar companions High resolution to measure mass of giant planets  High spatial resolution to identify extremely close background stars