1 WB/lct CCD OVERVIEW Kepler will have 42 CCDs 2,200 column x 1,024 row full frame CCDs Field of View (FOV) > 100 square degrees (113 w/ vignetting)

2 WB/lct Comets DATA: SOLAR SYSTEM Single example. Biased example – We are here! Meteorites Asteroids Giant Planets Terrestrial Planets Moons A great deal of information, But…

3 WB/lct KEPLER and The Planet Finder (TPF) Excerpts from the National Research Council (NRC) report with regard to TPF: “…. TPF will revolutionize major areas of planetary and non-planetary science… …...it is important to determine prior to the start of the mission that it is likely that there will be an adequate number of Earth-sized planets for TPF to study." (p. 112) National Research Council

4 WB/lct MORE PLANETARY SCIENCE Terrestrial planet multiplicity. Terrestrial planet coplanarity (~ 12% chance of seeing both Venus & Earth if either is seen). Single transits of ~30 cold Jupiters (SNR = 400).

5 WB/lct TRANSIT Transit observation by HST of a jovian-size planet orbiting hd Ten-minute to ten-minute binned data from several orbits have a precision of 60 ppm (Brown et al. 2001).

6 WB/lct BINARY SEPARATION

7 WB/lct MAIN SEQUENCE STARS

8 WB/lct PLANETS PER DURATION

9 WB/lct KEPLER SPACECRAFT Photometer Radiator Spacecraft Solar Array Sunshade High gain Antenna

10 WB/lct DETECTION CAPABILITIES

11 WB/lct TRANSIT PROPERTIES

12 WB/lct EXPECTED TRANSITS EXPECTED NUMBER OF GRAZING TRANSITS BY TARGET STARS 50% of target stars are binaries => 50,000 targets are binaries 20% have orbital periods of order days to weeks 10,000 stars with transit probabilities near 10% 1000 stars will show stellar transits Of these 1,000 stars, ~ 6.5% (i.e., 65) stars will show 1% deep transits ~ 1.4% (i.e., 14) stars will show 0.1% deep transits ~ 0.3% (i.e., 3) stars will show 0.01% deep transits 20% have orbital periods between a few months and a few years 10,000 stars with transit probabilities near 1% 100 stars will show stellar transits Of these 100 stars; ~ 6.5% (i.e., 6 ) stars will show 1% deep transits ~ 1.4% (i.e., 1.4 ) stars will show 0.1% deep transits ~ 0.3% (i.e., 0.3 ) stars will show 0.01% deep transits

13 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 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 5 hr for m v =12 solar-like star and 1-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 - Both SITe and EEV are thinned, back-illuminated, delta-doped, AR coated Limiting bright magnitude of m v =9 and full-well depth of 825 e - /µm 2 requires: - Defocus image to 5 pixel diameter and readout every 3 seconds.

14 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 quadrant 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 diameter: - Mitigates saturation (10 9 e - /hr) and sensitivity to motion; Control pointing to 28 millipixels (0.1 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.

15 WB/lct ORGANIZATION

16 WB/lct SINGLE TRANSIT SNR’S Approximate Single Transit SNR's for a 12th mag Star

17 WB/lct DETECTABLE SIZE Each plot is for a given stellar brightness. Planets of a given size are detectable to the left of each contour. Detection are based on a total SNR> 8 s and > 3 transits in 4 years. Detectable planet size vs. Orbital semi-major axis and star mass

18 WB/lct DETECTABLE STARS The solid lines show the number of dwarf stars of each spectral type for which a planet of a given radius can be detected at 8 . These numbers are based on 4 near-grazing transits with a 1-yr period and stars with m v < 14. The dashed lines show a significant increase in the number of stars when assuming 4 near-central transits. Number of stars that can be detected vs planet size as a function of stellar type

19 WB/lct SNR The three curves give the SNR for 4 combined transits about an m v =12 solar-like star at times of low, medium, and high stellar variability. SNR as a Function of Transit Duration and Stellar Variability

20 WB/lct DETECTABLE RADIUS Earth-sized transits are readily detectable for stars with variability comparable to that of the Sun. Effect of Stellar Variability on Detectable Planetary Radius

21 WB/lct Test bed: BRIGHT STAR EFFECT Within the planned Kepler Mission field-of- view there are several stars as bright as m v =4. To simulate the impact of a bright star in the field, fiber optics were used to generate m v =4 stars at various distances from stars in the field. The effect of a bright star does not raise the general system noise above the red line noise limit. Only the nearest star within a few CCD columns of the m v =4 star was significantly affected. Both its noise and apparent brightness increase.

22 WB/lct Test bed: S/C MOTION EFFECT In this 46 hour test the camera was moved at various amplitudes and rates characteristic of the spacecraft guidance system performance. The jitter model used predicted a 1  standard deviation in pointing of 0.01 arcsec in each axis, corresponding to 2.8 millipixels on the CCD. Deviations were typically less than 4  during the test, i.e., 11 millipixels. The test results show that the system noise is still below the maximum allowable noise except for a small number of deviant stars.

23 WB/lct SUMMARY The Kepler Mission is designed to detect hundreds of Earth-size planets by looking for transits. To demonstrate the technology to be utilized, a Testbed Facility has been built and operated with a flight type CCD. The facility simulates all of the features of the sky and the spacecraft/instrument that are important for the success of the mission. Optimum operating conditions for defocus, photometric aperture size vs stellar brightness and maximum operating temperature have been measured. The required photometric precision has been demonstrated while operating without a shutter during readout, having some saturated pixels in the brightest stars, working in a crowded field with a star density the same as planned for the mission, inclusion of spacecraft jitter, and over a dynamic range of five stellar magnitudes. Tests of comic-ray hits and field rotation (which occurs every three months during the mission) also do not appear to have detrimental affects. Transits have been injected and detected at the required statistical significance under all operating conditions during all tests. The Kepler Mission is ready for flight status.

24 WB/lct SPECTRAL TYPE

25 WB/lct TRANSITS OBSERVED BY VULCAN Cygnus #3047 Perseus #0831 Cygnus #3047 Cygnus #937 HD Cygnus #1433

26 WB/lct DETECTION RATE Expected detection rate for hot Jupiters Probability that: the target star is dwarf: 0.5 the star is single or a widely space binary: 0.5 to 0.8 the star has a hot Jupiter: 0.01 to 0.02 the orbital plane is correctly aligned:0.1 six weeks of data show at least three transits: 0.6 Product of the probabilities: 1.5 to 4.8 x10 -4 Yield = Product of probabilities times number of stars monitored = 1.5x10 -4 x 10 4 stars = 1.5 to 5 planets

27 WB/lct VULCAN Vulcan transit search of 6,000 stars for extrasolar planets OBJECTIVES: Monitor 6000 stars “continuously” for periods of at least 6 weeks Detect jovian-size planets in short period orbits Use Doppler-velocity measurements to determine mass and density TELESCOPE: Aperture: 10 cm Focal length: 30 cm Field of View: 7x 7 degrees Detector: 4096x4096 CCD with 9 m pixels