Collaborators:

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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
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Outline

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

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1500 FGKM M.S. Stars
Doppler Monitoring Begun 1987 Duration 20
Years Jupiter Analogs?
13 Years (5 AU)
11 Years (5.5 AU)
22 Years (7 AU)
Keck
Lick
Anglo-Aus. Tel.
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Stellar Sample - 1330 Nearby FGKM Stars
2500 with Mayor, Queloz, Udry, Pepe, Lovis,
BonfilsCochran, Endl, Hatzes, Latham, Noyes,
Sato, Others
Hipparcos Cat. d lt 100 pc
H-R Diagram

• Star Selection Criteria
• Vmag lt 10 mag
• (a few to Vmag 13)
• No Close Binaries
• Age gt 2 Gyr

. 1330 Target Stars
Lum
1.3 Msun
Target List Published (Wright et al 2005)
0.3 MSUN
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Wavelength Calibration
8 Significant Digits

• Echelle Spectrometer
• Resolution 60,000
• Iodine Abs. Cell
• Superimpose I2 lines
• Wavelength Calib.
• PSF Determination

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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
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Fiber Scrambler - Lick Observatory
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Standard Stars - 1.5-2.5 m/s
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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

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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 lt 50 pc)
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Typical non-detection
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Planet Candidates - Follow-up Needed
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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
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Properties of Super-Earths and Host Stars

• Excluding
• GJ 581e
• Corot-7
• Microlensing planets
• Pulsar planets

Howard et al. 2009, ApJ, 696, 75
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Known Planets in Eta-Earth Survey
33 planets orbiting 21 stars (out of 230 stars in
Eta-Earth Survey)
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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

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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
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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
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HD 126614 B

• New M dwarf!

• Detection with Palomar/PHARO camera
• M dwarf companion to planet host
• M 0.32 Msun
• rAB 45 AU

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)
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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
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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
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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 (V12)

KeckHET
Howard et al. 2009, ApJ submitted
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Questions? and
Happy Birthday to my son Ian who completes his
first orbit around the sun today
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Extra Slides
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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
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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
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Precision of Eta-Earth Observations

• Velocity RMS of Eta-Earth stars

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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
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Stellar Spectrum Echelle
4000 Pixels on CCD
2 m/s ? 0.001 pixel
(80 Si atoms)
l Calib 8 sig. fig. (v/c).
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Improving Velocity Precision (2)
Star multi-exposure, dithered templates -gt
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 -gt better de-convolution
templates
Low amplitude planets depend on precision
velocities
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Iodine Cell Method
Iodine Cell Method
Photo courtesy of Laurie Hatch
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Fiber Scrambler - Lick Observatory
Design by Julien Spronck, SFSU
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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
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All Known Exoplanets Mass Distribution

• Rise toward
• lower masses
• to 1 MSAT
• dN/dlogM
• Constant
• 35 Sub-Saturns

Detection Limit 0.2 MJUP _at_ 1 AU
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RV Observations
Ida/Lin Theory
Ida Lin 2009, ApJ, 685, 584
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RV Observations
Eta-Earth Sensitivity
Ida/Lin Theory
Ida Lin 2009, ApJ, 685, 584
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Questions?