Planet search with HDS at Subaru1Tokyo Institute of TechnologyHiroki Harakawa,

Bunei Sato, Shigeru Ida, Yasunori HoriTITech,Masashi OmiyaTokai Univ., Eri ToyotaKobe Science Museum, Debra A. Fischer (Yale Univ.)#13Todays MENUN2K consortium ~a planet searching project~StrategyCurrent StatusImproving the precision of RV analysis for Subaru/HDS

Summary22consortiumA collaborative planet searching project between US and Japanese teamAiming to detect Transit PlanetsRadial Velocity observations with I2 cellHigh Dispersion Spectrograph (Subaru/HDS)The RV precision: 45m/sSurveying for Hot Jupiters around ,, dwarfs & subgiantsSubaru holds 630 targets3

KeckMagellanSubaru3StrategyNext 2,000 (N2K) starsV < 10.5, d < 110 pc, FGK V, IVHigh priority to metal-rich stars

3+1 nights observation3 observations in 3 nights in a row1 scatter > 20 m/s follow up1 scatter < 20 m/s dropVerify candidates to reject binary system in 1 month later4Current Status of Subaru N2KOrbital determination to 4 candidatesShort period (P < 25 d) and transiting!!HD149026b(Sato et al. 2005, ApJ)HD17156b(Fischer et al. 2007, ApJ)Long period (P > 400 d) and low eccentricity (e < 0.1)HD16760b(Sato et al. 2009, ApJ)HD38801b(Harakawa et al. submitted to ApJ)Above 40 planetary system candidates

Overall status of N2K consortiumDiscovered 23 exo-planetsDetection rate of Subaru 10MJUP, P > 100 d, e < 0.1

A small improvement of the RV analysis methodModified how to select data for stellar templateImprovement of long term precision of RV10 m/s to 5 m/sFurther improvement should be made< 3 m/s1818The shape of IP is affected by the optical condition(ex: temperature, humidity) changes every moment in HDS, HIDES is also determined by seeing size

19

1920

The shape of IP is affected by the optical condition(ex: temperature, humidity) changes every moment in HDS, HIDES is also determined by seeing size

20Stellar templateS(+) Sato et al. (2002)

Iobs

5S/N2110

Result of incorrect IP modeling

22IP (Instrumental Profile)PSF (Point Spread Function)IP(convolution)23pixelI (photon count)pixelI (photon count)*IP23HD16760bHD16760(G5V, V=8.7)M1=0.78M, R1=0.81R,[Fe/H] = 0.067

Period:466.5 dSemi-amplitude:407.7 m/sMin. mass:13.1MJUPSemi-major axis:1.1AUEccentricity:0.084

Low-eccentricity brown dwarf24

NEWSato et al. 2009, ApJ32003600400044004800JD(-2450000)HD38801bHD38801(K0IV, V=8.26)M1=1.36M, R1=2.53R,[Fe/H] = 0.26

Period:696.0 dSemi-amplitude:200.0 m/sMin. mass:10.7MJUPSemi-major axis:1.7AUEccentricity:0.03

Super massive planet with almost circular orbit25

NEWHarakawa et al. submitted2001000-100-200Radial velocity [m/s]38004000420044004600JD(-2450000)

HD38801bHD16760bM sin i [MJUP] or 26 2627

0.5Strategy14000V 26 -> 236 Cet, Procyon37

HIDES 2006/20075.6 m/s (Sato et al. 2002) 2.9 m/s < 3 m/s Cet Cet, Procyon38

HIDESLick200210m/sRVLickProcyonKambe et al. 2008Sato et al. (2002)IP-Cet 2.9m/s Procyon 10 m/s 39CCDpixelDoppler-shift40()

40S/N(Butler et al. 1996)

41HDS

S/N or

i: i

iiwave length (pixel)I (photon count)i41S/N=150, R=60,000, Na-D line (=5890)

42HDS2.0[m/s]42HDS HD940734 [m/s] 10 [m/s] 143HDS

433444 (Lick Observatory)pixelwavelengthpixelwavelength343 ()4rINT4.45 (m/s)4.38 (m/s)rBIN5.49 (m/s)4.64 (m/s)44

4545

46m*mp sini(sini)

Doppler shift

47

(z)target star

47

.48m*mp sini(sini)

Doppler Shift 49

target star(z)(RV)

Keplers 3rd Law

m2p m1*

m*mp sini(sini)

50.Mayor

Th-Ar

51

52a:e:i :::T:

(z)target star

ESO 3.6-m Telescope

HIDES(High Dispersion Echelle Spectrograph)photo : B Sato