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Collaborators: Geoff Marcy Debra Fischer John Johnson Jason Wright Katie Peek Greg Henry

The NASA-UC Eta-Earth Survey At Keck Observatory - Andrew Howard - Townes Post-doctoral Fellow, UC Berkeley. Collaborators: Geoff Marcy Debra Fischer John Johnson Jason Wright Katie Peek Greg Henry Matt Giguere Howard Isaacson Julien Spronck Kevin Apps Jeff Valenti Jay Anderson

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Collaborators: Geoff Marcy Debra Fischer John Johnson Jason Wright Katie Peek Greg Henry

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  1. The NASA-UC Eta-Earth SurveyAt Keck Observatory- Andrew Howard - Townes Post-doctoral Fellow, UC Berkeley Collaborators: Geoff Marcy Debra Fischer John Johnson Jason Wright Katie Peek Greg Henry Matt Giguere Howard Isaacson Julien Spronck Kevin Apps Jeff Valenti Jay Anderson Nikolai Piskunov David Bernat Mike Endl Bill Cochran HD 7924b

  2. Outline • RV Planet Searches • Improving Doppler Precision • Eta-Earth Survey • Announce 5 New Planets !!

  3. Doppler Monitoring Begun: 1987 Duration: 20 Years + Jupiter Analogs? 1500 FGKM M.S. Stars 13 Years (5 AU) 11 Years (5.5 AU) 22 Years (7 AU) Keck Lick Anglo-Aus. Tel.

  4. Stellar Sample -1330 Nearby FGKM Stars~2500 with Mayor, Queloz, Udry, Pepe, Lovis, BonfilsCochran, Endl, Hatzes, Latham, Noyes, Sato, Others H-R Diagram Hipparcos Cat. d < 100 pc Star Selection Criteria: • Vmag < 10 mag (a few to Vmag =13) • No Close Binaries • Age > 2 Gyr . 1330 Target Stars Lum 1.3 Msun Target List: Published (Wright et al 2005) 0.3 MSUN

  5. Wavelength Calibration 8 Significant Digits • Echelle Spectrometer • Resolution: 60,000 • Iodine Abs. Cell • Superimpose I2 lines • Wavelength Calib. • PSF Determination

  6. Improving Velocity Precision - All Stars New Pipeline: by John Johnson, also Debra Fischer for Lick data Re-compute 2004-present velocities: equal or better performance on standard stars D l DOP Intrinsic Stellar Spectrum (shifted) Observed Spectrum Iodine Transmission Point Spread Function

  7. Fiber Scrambler - Lick Observatory See Poster by Julien Spronck: “FINDS: Fiber-optic Improved Next-generation Doppler Search for Exo-Earths” Design by Julien Spronck, SFSU

  8. Standard Stars - 1.5-2.5 m/s

  9. How Common are Low-mass Planets? • Burning Debate! • Theory predicts very few super-Earths and Neptunes in short-period orbits • Swiss group claims that 30% ± 10% of • GK dwarfs have rocky or Neptune planets • inward of 50-day orbits • Our initial results show relatively few Super-Earths and Neptunes

  10. NASA-UC Eta-Earth Program • RV survey of 230 nearby GKM dwarfs • Search for low-mass planets (M sini = 3-30 MEarth) • Constrain population of low-mass planets and planet formation theory 40% G stars 40% K stars 20% M stars Eta-Earth stars Hipparcos (d < 50 pc)

  11. 1 high-cadence run 20+ observations over 4 years Typical non-detection

  12. Planet Candidates - Follow-up Needed

  13. HD 7924b - Super-Earth Detection Star: HD 7924 (K0V) Planet: M sin i = 9.3 MEarth P = 5.398 d e = 0.17 (consistent with circular) Howard et al. 2009, ApJ, 696, 75

  14. Super-Earths Hosts: • Low Mass • Metal poor (controversial) Super-Earth Planets: • Multi-planet systems Properties of Super-Earths and Host Stars Excluding: • GJ 581e • Corot-7 • Microlensing planets • Pulsar planets Howard et al. 2009, ApJ, 696, 75

  15. By Mass: 14 Jupiters 7 Saturns 6 Neptunes 6 Super-Earths Known Planets in Eta-Earth Survey 33 planets orbiting 21 stars (out of 230 stars in Eta-Earth Survey)

  16. Next Steps for Eta-Earth Survey • Finish survey observations (~6 months) • Intensive follow-up observations of best low-mass candidates • Announce more super-Earths and Neptunes! • Transit searches for announced and candidate low-mass planets • Statistical study of low-mass / short-period exoplanets in Eta-Earth Survey

  17. HD 24496 b New Planet! • Detection with Keck • Period = 4.3 yr • Msini = 0.32 MJ • Ecc = 0.3 • Eta-Earth star • Known stellar companion Howard et al. 2009, ApJ submitted

  18. HD 126614 Ab New Planet! • Detection with Keck • Period = 3.4 yr • Msini = 0.4 MJ • Ecc = 0.75 • [Fe/H] = +0.56 highest in SPOCS! Howard et al. 2009, ApJ submitted

  19. HD 126614 B New M dwarf! • Detection with Palomar/PHARO camera • M dwarf companion to planet host • M = 0.32 Msun • rAB = 45 AU HD 126614 B HD 126614 A Observations by David Bernat and Jason Wright Howard et al. 2009, ApJ submitted AO Image from Palomar/PHARO camera of: HD 126614 A (G dwarf; planet host) HD 126614 B (M dwarf)

  20. HD 13931 b New Planet! • Detection with Keck • Period = 12.5 yr • Msini = 1.9 MJ • Ecc = 0.09 • Jupiter analog orbiting solar twin Howard et al. 2009, ApJ submitted

  21. HD 34445 b New Planet! • Detection with Keck + HET • Period = 2.7 yr • Msini = 0.75 MJ • Ecc = 0.49 • 2nd planet? KeckHET Howard et al. 2009, ApJ submitted

  22. Gl 179 b New Planet! • Detection with Keck + HET • Period = 6.3 yr • Msini = 0.9 MJ • Ecc = 0.26 • M dwarf • [Fe/H] = +0.3 • Faint (V=12) KeckHET Howard et al. 2009, ApJ submitted

  23. Questions? and … Happy Birthday to my son Ian who completes his first orbit around the sun today

  24. Extra Slides

  25. RV Precision / Noise HARPS Keck/HIRES Eta-Earth Survey stars GKM Chromospherically quiet ~10-100 observations each Mayor and Udry, 2008,Phys. Scr. T130, 014010

  26. Extrasolar Planet Phase Space Extrasolar Planet Phase Space Current harvest of ~350 planets (RV): empirical constraints on planetary system formation. Jupiter & Neptune appear to be the tip of the “planetary iceberg.” Simulations from Ida & Lin

  27. Precision of Eta-Earth Observations Velocity RMS of Eta-Earth stars

  28. Progress on Eta-Earth Sample (2) Progress on Eta-Earth Sample ~75% of stars have 20+ observations ~75% of stars have 1 high-cadence run ~30 low-mass candidates being followed-up Progress on 20+ obs/star Progress on 1 high-cadence run/star Done Done

  29. Stellar Spectrum: Echelle 4000 Pixels on CCD 2 m/s  0.001 pixel (80 Si atoms) l Calib: 8 sig. fig. (v/c).

  30. Improving Velocity Precision (2) Star: multi-exposure, dithered templates -> higher S/N, sub-pixel features De-convolution: old: Jansen - float pixels & smooth spectrum new: model spectrum by pushing on Guassians on floating nodes; fit by 2 Iodine: new, higher resolution scan of Keck/HIRES iodine cell PSF: better iodine spectrum improves PSF -> better de-convolution & templates Low amplitude planets depend on precision velocities

  31. Iodine Cell Method Iodine Cell Method Photo courtesy of Laurie Hatch

  32. Fiber Scrambler - Lick Observatory Design by Julien Spronck, SFSU

  33. Dithered Templates Take multiple stellar template spectra Dither echelle angle Sub-pixel translation of stellar spectrum Recover sub-pixel spectral details Higher S/N, too. Intensity Stellar spectrum Residuals (X10) Wavelength Jay Anderson, STScI

  34. All Known Exoplanets: Mass Distribution • Rise toward • lower masses • to 1 MSAT • dN/dlogM ~ • Constant • ~35 Sub-Saturns Detection Limit: ~ 0.2 MJUP @ 1 AU

  35. RV Observations Ida/Lin Theory Ida & Lin 2009, ApJ, 685, 584

  36. RV Observations Eta-Earth Sensitivity Ida/Lin Theory Ida & Lin 2009, ApJ, 685, 584

  37. Questions?

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