ドレイク方程式ドレイク方程式

フランク・ドレイク（米、1930-）

SETI（地球外知的生命探査）の創始者

地球外の知的生命が宇宙に発した電波を検出する

最初のSETI: オズマ計画（1959）

2013.12.27 9:35 - 10:10 (30+5 min)

Motohide Tamura 田村元秀2013.12.27 9:35 - 10:10 (30+5 min)

Motohide Tamura 田村元秀Motohide Tamura 田村元秀The University of Tokyo / NAOJ

E l t P j t G / Offi

Motohide Tamura 田村元秀The University of Tokyo / NAOJ

E l t P j t G / OffiExoplanet Project Group / OfficeNew project page - http://esppro.mtk.nao.ac.jp

Exoplanet Project Group / OfficeNew project page - http://esppro.mtk.nao.ac.jp

Talk ContentsIntroduction

Talk ContentsIntroduction

Exoplanet detectionExoplanet detection

Image Giant Planets!g

Catch 2nd Earths!

Progresses in otherth d (RV TR)methods (RV,TR)

Future plansFuture plans

Various observational progresses led the detection ofmore than 4000 planets and planet candidates by nowmore than 4000 planets and planet candidates by now

g g e) pler

ber

3000

3500

3000

3135r ns

ing

mag

ing

ase)

mag

ing

dph

ase

Kep

Num

b

2500

Dop

pler

Tran

sit

Mic

role

nD

irect

imfir

stph

a

Dire

ctim

seco

nd

dates

ativ

e N

1500

2000

D T M D (f D (s

.12:

rmed

rcandid

mul

a

1000

1500

of

2013

50

confi

00

Keple

Cu

500

1 7 7 14 25 44 56 85 112 143 176 204265

327409

523 As

105

340

Discovery Year0

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

Exoplanets in Brief 2013.12 ~1050 (~3400) planets (candidates)

% >60% of G stars have planets

~80 (~800) super-Earths (candidates) 80 ( 800) super Earths (candidates)

>350 Earth-size (<1.4 RE) Kepler Pl-Can.

>900 multiple planet systems

Max 6 planets Max 6 planets

Lightest candidate of ~1 MEarth

Smallest candidate of 0.6 REarth

Nearest candidate at 4 light years Nearest candidate at 4 light years

Central stars: 20 MJUP brown dwarf – 4.5 MSUN giant

If you see our solar system from distant (say 10pc)

If you see our solar system from distant (say 10pc)from distant (say 10pc) …from distant (say 10pc) …

You need:Hi h ti l l ti- High spatial resolution

- High sensitivity- High contrast

RV or Doppler method extra precise velocity measurements

Planet Hunting Methods: Indirect

Star itself rotate around the center-of mass when planets revolve

RV or Doppler method: extra-precise velocity measurements１Mo

of-mass when planets revolve. To measure the period velocity change

of the star by spectroscopy (Doppler or radial velocity method)

Radial

or radial velocity method) Current accuracy: ~1 m/s or less

measuring human walking speed of s star from distance

Velocity

Sun speed due to Jupiter～13 m/sec

Most planets (>80%) detected with this method before Kepler mission. Semi-MA (AU)

y

（m/s)

Transit, gravitation lensing, pulsar timing

BUT not detected photons from planets (INDIRECT method)

Planet Induced Vlocity

Earth 0 09 m/s(INDIRECT method)

Minimum: ~1 Earth-mass planet

To measure its positional shift is

Earth 0.09 m/s

Jupiter12 m/s

/ To measure its positional shift is“Astrometry method”. Uranus 0.3 m/s

Planet Hunting Methods: IndirectTransit method: to measure brightness

change with a change of planet revolution.g g p

Eclipsing companionEclipsing companion（Only when

nearly edge-on）↓↓

Low probability, soObserve many stars

Planets T D Prob-----------------------

Photometric accuracyFrom space（typically

Jupiter 12yr 1% 1/1000Uranus 84yr 0.1% 2/10000Earth 1yr 0.01% 5/1000H t J 4d 1% 1/10

time

（typically0.2% from ground,

0.002% from space）

Hot Jup 4day 1% 1/10

Exoplanet Internal Structureswith both transit+RV datawith both transit+RV data

Kepler-78b

Howard+2013

Detection Methods: They are complementary

Indirect method Direct method

Doppler method

Velocity shift due to

Planet b

Transit method

Velocity shift due toplanet orbital motion= RV method

St ATransit method

Brightness changedue to planetary transit

- High resolution & highContrast imaging

Star A

Brightness changedue to microlensing

- Emission from planetdirectly images- Ultimate planet

Microlensing method

Seeing is

Astromenrt method

due to microlensingEffectNo repeatable!

observing method- No conclusive reportbefore 2008

Believing!

Astromenrt method

Positional shift due toPanet orbital motionGAIA mission hopeful

⇔ Different methodsdetect different type planets

SEEDSSEEDSSEEDSIFU

SEEDSIFUIFU

Hi h S tIFU

Hi h S tHigh-res SpectroscopyHigh-res Spectroscopy

SEEDS –Strategic Explorations of Exoplanets and Disks with Subaru First “Subaru Strategic Program (SSP)” Subaru

HiCIAO

First Subaru Strategic Program (SSP) 120 Subaru nights in 5 years from 2009; ~5/6 finished by now Direct imaging and census of giant planets in the outer regions

Subaru

(a few AU - ~40 AU) around ~500 solar-type and massive stars Exploring protoplanetary disks and debris disks for the origin

of their di ersit and e ol tion at the same radial regionsof their diversity and evolution at the same radial regions Direct linking between planets and protoplanetary disks

Resolution

⇒Resolution=0.1-0.2”

Resolution=0.05-0.1”

ContrastImproved by ~10

？⇒

00 lSolar-System ？>100AU scale

w/ CIAO

Solar SystemScale (<50AU)

w/ HiCIAO

Direct Imaging Relies on Luminosity Evolution(Current imaging detects thermal emission from young planets vs. SEEDS category)

SFRs (Taurus, etc.) Open c. (Pleiades, etc.) Solar Sys.

YSO MG & DD OC NS

ontrast

Stars

ntrast

nd low-co

Browndwarfs

SEEDS is targeting youngbright and medium-contrast

high-con

Bright a

dwarfsbright and medium contrastself-luminous planets

Faint and

Planetmass

- gold dots: 50% of deuterium- magenta dots: 50% of lithium has burned

F

objecthas burned.

Burrows+

Planet Formation TheoriesCore accretion model = Cold start Gravitational Instability = Hot start

vs.

Evolution of5 Jupiter mass object

y(Lo)

~4 times

minosity

~2 timesH t t t

Lum Hot start

Cold start faint planet predicted

Burrows+Marley+

Age (10^8 yr)

faint planet predicted Marley+Spiegel+Quinn+

Exoplanet imaging with Subaru Among 30 directly imaged ones, only

<10 Solar-system planets arnounnormal stars

GJ 758 b （2009） First Sun-like star planetp

candidate imaged κ And b （2013） Most massive star’s planet

imaging discoveryGJ 504 b （2013 A t） GJ 504 b （2013 August） Least massive planet: “2nd

Jupiter”imagedJupiter imaged Independent of the models PR:>400 online media Japan PR:>400 online media, Japan-

US-Germany-France-China-India-etc.

Image of A Cold Jovian Planet: GJ 504b

GJ 504b: Smallest Mass Planet ever Imaged

Image of A Cold Jovian PlanetGJ 504b: Unique Atmosphere ?

Disk scattered Light by Polarization Imaging

Disk fine structuresdown to 5-10AUfrom central star

Hashimoto et al. 2011 w/HiCIAO Fukagawa et al. 2004 w/CIAO

SEEDS disk galleries in <0.1 arcsec resolution

Detection of morphological diversity ofp g yprotoplanetary disks at wide-orbit planet radii.

Signpost of planet

Very Young Planets in Disks Detected ??Still under debate in this fieldStill under debate in this field

Kraus+2013

Keck+OSIRISCharacterization

Keck+OSIRISwith IFU

Barman+2013

New Technique: High Resolution Line Spec.

Brogi+2103

ndndndnd

KeplerKeplerpHARPS

pHARPS

IRDIRDSEIT & moreSEIT & more

Kepler mission: summary• Aim: make census of Earth-like(0.5-1.0 MEarth) planets around Sun-like starlike star

• Method: continuously monitor ~0.15million stars with 42 CCDs

S~1kpc

• Telescope: 0.95m Schmidt telescopew/ ~10dx10d fov(>400 times Subaru)

• Photometric accuracy goal:

1kpc

Photometric accuracy goal:20 ppm（0.002%）=> Earth transit detection (84ppm) with 4 sigma

In orbit: 40 ppm

ppm) with 4 sigma・NASA discovery program・Launch: 2009.3.7Launch 2009.3.7・Duration: 3.5 + 3.5 years (2016)

2013.8 Failure~ $・Cost: ~US600M$

(plan started in 1994!, failed several times)

Kepler planet candidates discoveredin the first 22 monthsin the first 22 months

<1.25 REEarth size

Super‐Earth sizep

Neptune size

Jupiter size

２７４０ Kepler planet candidates (122 confirmed) Batalha+2013

Kepler planet candidates: Period vs. Size

Real 2nd EarthRe 2 E tZone?

Occurrence of Planets (P<85 d)17% 21% 20% 2% 2% Total=62%

Small

Fressin+2013

Habitable Kepler Planets

惑

約60個のハビタブル惑星（重いものも含む）惑

星の

木星

（重いものも含む）

の半径

海王星（地球

海王星

球を１ 地球

とするる）惑星の平衡温度（大気効果を考慮すると摂氏0-100度）

Most Kepler Planets are too faint for Follow-up

Kepler planets

Almost no overlap!

惑星の個

Doppler planets

個数

可視光での明るさ

“Nearby” planet hunting other than Kepler needed!

可視光での明るさ

How to characterize &d

Subaru 8m: a finder less massiveSun

image 2nd earth?Subaru 8m: a finderTMT 30m: an imager

less massiveSun

Subaru: Infrared Doppler searches for nearby second Earths

TMT 30m: an imagerfor nearby second Earths

TMT: Then directly imaging them around M starsthem around M stars Slightly preferable contrast (10^-8)(10 8)

Much better resolution (0.02" observable)

Earlier than from space?

SEIT (松尾、小谷、村上、河原、田村)

Subaru's next step: Earth-like planet hunting with IR Doppler Instrument

赤外線の利点を活かし 主流の

hunting with IR Doppler Instrument 赤外線の利点を活かし、主流の

可視光ﾄﾞｯﾌﾟﾗｰ法の限界克服。 可視光ﾄﾞｯﾌﾟﾗｰ法は太陽型星ﾒｲﾝ。

軽い恒星（M型星）は宇宙に数多い 軽い恒星（M型星）は宇宙に数多いが、可視光では暗く、赤外線が有利。

赤外線ドップラー法は未開拓。8m望遠鏡の専用装置はIRDが唯一8m望遠鏡の専用装置はIRDが唯一。

赤外線ドップラー法によって地球質量の惑星をM型星の

恒星の

m/s

10地球質量 本研究が狙う、恒星

地球質量の惑星をM型星のﾊﾋﾞﾀﾌﾞﾙｿﾞｰﾝに検出。 HZが恒星に近く、周期が短い。

ドップラー

6

3可視光

赤外線

の型と最低惑星質量現状精度（赤外）

標準惑星形成理論はM型星にも多数の地球型惑星の存在を予測（右上）。

ケプラー衛星による統計も追い風。

ー速度振れ

1 光有利

線有利

目標速度精度

口径30m望遠鏡による地球型直接観測へ一番乗りする好対象。

れ幅

恒星質量（太陽質量）太陽型星

IRD Developments in Progress

補償光学より

光ファイバー

より

M型星の周期的速度変動を1m/s精度で検出

ファイバー入射光学系

レーザーコムのスペクトル

赤外ナスミス焦点 恒星のスペクトル

光ファイバー

分光器

ESB 床（最も安定）

分光器システムレーザー周波数コムシステム

TMT + SEIT Detectability・Assumptions: -Planets at inner edge of habitable zone.

-SEIT ideal performanceSEIT ideal performance・Results: 10 Sun-like stars, 90 light-weight stars (5 hrs, 5σ)

n

1.0

of th

e Sun

Solar System 10 -7

t

SEIT for 5sigma

of m

ass o

Gl 581

10 -8

Con

btra

st

0.3

ss in

 unit 

10 -9

-Pla

netC

0 1 1 00.1

10 0Stellar m

a 10 -10S

tar-

0.1 1.0 10.0Semi‐major Axis (AU)

S 10 -11

Star-Planet Separation (arcsec)0.01 0.1 1.0

JWST 2018 &WFIRST/AFTA ~2024?WFIRST/AFTA 2024?

WFIRST/AFTA ~2024?

SUMMARYSUMMARY More than 1000 exoplanets (+3400

candidates) have been detected mainlyby indirect methods.

The next milestones have just come of (1) E th l t d t ti d (2)(1) Earth-mass planet detection and (2) further direct imaging studies (such as the SEEDS project).the SEEDS project).

Characterizations of giants and super-earths have just started.j

Various new techniques and instrument developments ongoing.

How Japan can contribute in the next 10-20 years?

Synergy with various fields (astrobiology).

良いお年をExoplanet/Disk community is now grownExoplanet/Disk community is now grown

significantly in these ten years !!g y y

HiCIAO+IRCS+AO188 >> SEEDSHiCIAO+IRCS+AO188 >> SEEDSThen SCExAO+AO188+IRD+CHARIS