Spectroscopic search for atmospheric signature of transiting extrasolar planets

Spectroscopic search for atmospheric signature of transiting extrasolar planets

Department of Physics, University of TokyoYasushi Suto

http://hubblesite.org/newscenter/archive/

2001/38/

Post-Nishinomiya-Yukawa Symposium (November 5, 2004) “Origins: From First Objects to Extrasolar Planets”

Post-Nishinomiya-Yukawa Symposium (November 5, 2004) “Origins: From First Objects to Extrasolar Planets”

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Non-trivial and amazing success of observational cosmology

Tegmark et al. (2004)

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So what’s next ?Precision cosmology, not yet ?Precision cosmology, not yet ?

We have to move on; determine all the cosmological parameters We have to move on; determine all the cosmological parameters within 0.1% accuracy, for instance.within 0.1% accuracy, for instance.For what ? Really interesting ? Can convince taxpayers ?For what ? Really interesting ? Can convince taxpayers ?

Beyond precision cosmology ?Beyond precision cosmology ?Stop playing with the Stop playing with the values of parametersvalues of parameters, but try to understand , but try to understand their meaningtheir meaning, i.e., matter context in the universe, i.e., matter context in the universe

Nature of dark matter and dark energyNature of dark matter and dark energyHighest Highest redshiftredshift objects, First objects in the universeobjects, First objects in the universeinitial conditions (physical model of inflation)initial conditions (physical model of inflation)……

Revisit the cosmological observations in a more general frameworRevisit the cosmological observations in a more general frameworkkEquation of state of the universeEquation of state of the universeValidity of the cosmological principleValidity of the cosmological principleValidity of the general relativity on cosmological scalesValidity of the general relativity on cosmological scales

Or simply beyond cosmology itself !Or simply beyond cosmology itself !Religion (i.e., Religion (i.e., AnthropicAnthropic principle), principle), Extrasolar planetExtrasolar planet,, ,,,,,,

xxx

xxx

xxx

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A naive point of view of a simpleA naive point of view of a simple--minded minded cosmologist for cosmologist for extrasolarextrasolar planet studyplanet study

Just startedJust startedfirst discovery in 1995 ! first discovery in 1995 !

easier to convince taxpayerseasier to convince taxpayersother sciences became too detailed or too matured other sciences became too detailed or too matured to achieve really fundamental contributionto achieve really fundamental contributionWhat fraction of people can appreciate MWhat fraction of people can appreciate M--theory ?theory ?

directly related to directly related to one of the most one of the most fundamental questionsfundamental questions

origin of lifeorigin of lifeMaybe not during my lifetime, but this is Maybe not during my lifetime, but this is exactly why I am attracted by this fieldexactly why I am attracted by this field

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“Evolution” of extra-solar planet science

1

10

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10000

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1994

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# of all papers posted/year/earth

# of papers with “planet”in title or abstract

/year/earth

Terr

estr

ial p

aper

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mat

ion

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tory

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The first astro-ph paper with a word “planet” in its abstract

AstroAstro--ph/9309052ph/9309052C.AlockC.Alock et al. et al. Possible Gravitational Possible Gravitational MicrolensingMicrolensing of a Star of a Star in the Large in the Large MagellanicMagellanic CloudCloud

…… A less exotic alternative is normal matter in the form A less exotic alternative is normal matter in the form of bodies with masses ranging from that of a large of bodies with masses ranging from that of a large planetplanet to a few to a few MMsunsun……

Needs better criteria to remove falseNeeds better criteria to remove false--positivespositives……

A seminal paper, but not a planet paper indeedA seminal paper, but not a planet paper indeed

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Subaru observation

“Spectro-photometric search for scattered light from HD209458b”

S02B-16 on October 24 and 26, 2002Yasushi Suto, Norio Narita (Univ. of Tokyo)Toru Yamada, Wako Aoki (National Ast. Obs. Japan)Bun-ei Sato (Kobe Univ.)

Edwin L. Turner , Brenda Frye (Princeton Univ.)Josh Winn (Harvard Univ.)

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On-going three projects with HDSSearch for the planetary atmosphere from the ground observation

HHαα absorption analysis completed; upper limit absorption analysis completed; upper limit ～～0.1%0.1%Winn et al. PASJ 56(2004) 655Winn et al. PASJ 56(2004) 655 (astro(astro--ph/0404469)ph/0404469)Analysis of other lines in progress (Narita et al. 2004)Analysis of other lines in progress (Narita et al. 2004)

Constraining the stellar spin and the planetary orbital axes from the Rossiter-McLaughlin effect

New analytic formulae (Ohta, Taruya & Suto 2004; New analytic formulae (Ohta, Taruya & Suto 2004; astroastro--ph/0410499)ph/0410499)

Search for reflected light from planetsJust started collaboration with a group at St. Andrews Just started collaboration with a group at St. Andrews University (A. Cameron, C. Leigh, University (A. Cameron, C. Leigh, ……))

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Orbital phase and radial velocity of HD209458b in our observing run

Subaru/HDS

previous velocity curve (Wittenmyer et al. 2003)

Winn et al. PASJ 56(2004) 655, astro-ph/0404469

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search for Hαabsorption due to the atmosphere of

HD209458b

4861.344861.34ÅÅHHββ6562.816562.81ÅÅHHαα

4340.484340.48ÅÅHHγγ

5895.945895.94ÅÅNa Na I (D1)I (D1)5889.975889.97ÅÅNa Na I (D2)I (D2)

Hα

Fractional residu

al

In TransitIn Transit

HHααTelluric spectrumtim

eTemplate steller spectrumWinn et al. (2004)

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The most stringent upper limit on the Hαabsorption in the atmosphere of HD209458b

Hα fractional absorption

HHαα absorption

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See poster B20 (Josh Winn) for details

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Other lines (preliminary results)

Hβ

Na (D1) Na (D2)

No robust additional absorption signatures detected so far.

fractional upper limits 0.1-0.3%

Narita et al. (2004), in preparation

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Ask Norio Narita for details

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The Rossiter-McLaughlin effect

planetstar

Approaching part

Receding part

Shadow of the planet

Mean positionof wavelength

Time-dependent asymmetry in the stellar Doppler broadened line profile an apparent anomaly of the stellar radial velocity. originally discussed in eclipsing binary systems

Rossiter (1924)McLaughlin (1924)

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Radial velocity anomaly due to Radial velocity anomaly due to the the RossiterRossiter--McLaughlin effectMcLaughlin effect

planet

Spin axis of the star

Rad

ial v

eloc

ity

anom

aly

time

Planetary transit

Planetary orbital axis with respect to Planetary orbital axis with respect to the stellar spin axisthe stellar spin axis

They are parallel in the case of HD209458They are parallel in the case of HD209458How about the other transiting planets ?How about the other transiting planets ?

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Spectroscopic transit signature: the Rossiter-McLaughlin effect

Origin of angular momentum

in transit

out of transit

Stellar rotation and planetary orbitQueloz et al. (2000) A&A 359, L13

ELODIE on 193cm telescope

HD209458 radial velocity datahttp://exoplanets.org/

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Analytic templates for the velocity anomaly due to the Rossiter -McLaughlin effect

Limb darkening: B= 1- ε (1-cos θ)

Accurate analytic formulausing perturbation theory

Ohta, Taruya & Suto(astro-ph/0410499)

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Dependence on 10 parametersExample for HD209458

Velocity anomaly divided by the fractional uncertainty of each parameter

(Ohta, Taruya& Suto 2004)

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For further details, see poster B13 by Yasuhiro Ohta and Atsushi Taruya

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Possible constraints on TrES-1 systemR

adia

l Vel

ocit

y an

omal

y

time

ε=0.64

ε=0 (no limb darkening)P

roje

cted

mis

alig

nm

ent

angl

e [d

eg]

Stellar rotation velocity [m/s]

Proposal submitted to Subaru (PI: N.Narita)Mock data analysis using the parameters estimated by Alonso et al. (2004) and the analytic templates by Ohta, Taruya and Suto (2004)

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Search for scattered light from HD209458bSearch for scattered light from HD209458b

Statistical search Statistical search for the scattered for the scattered components components DopplerDoppler--shifted at shifted at vvpp(t) from the (t) from the stellar absorption stellar absorption lines.lines.The spectral The spectral resolution of HDS resolution of HDS ((λ /∆λλ /∆λ=50000) is =50000) is 10 times better 10 times better than that of STIS, than that of STIS, HST (HST (λ /∆λλ /∆λ=5540).=5540).

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A possible roadmap of A possible roadmap of sciences of sciences of extrasolarextrasolar planetplanet

Discovery phase of gas giant planetsDiscovery phase of gas giant planetsDiscovery phase of planetary atmosphereDiscovery phase of planetary atmosphereDetailed spectroscopic study of planetsDetailed spectroscopic study of planetsDiscovery of terrestrial planetsDiscovery of terrestrial planetsIdentifying BiomarkerIdentifying Biomarker

RedRed--edge of edge of extrasolarextrasolar plant ?plant ?Discovery of Habitable planetDiscovery of Habitable planetDiscovery of Extraterrestrial lifeDiscovery of Extraterrestrial life

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Astrobiology ? Not yetAstrobiology ? Not yetDiscovery of Discovery of extrasolarextrasolar planets is a wonderful planets is a wonderful breakthrough in astronomy (and philosophy, maybe)breakthrough in astronomy (and philosophy, maybe)

But mere discovery has no biological informationBut mere discovery has no biological information

How can we identify the signature of life ? How can we identify the signature of life ? BiomarkerBiomarker

Suppose our earth is Suppose our earth is located at 10pc away. Can located at 10pc away. Can we identify any signature we identify any signature of life from photometric of life from photometric and spectroscopic data and spectroscopic data alone ?alone ?

EarthEarth--shineshinehttp://modarch.gsfc.nasa.gov/http://www.nasa.gov/home/index.html

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Red edgeRed edge of ((extrasolarextrasolar) plants: ) plants: a biomarker in extrasolarextrasolar planetsplanets

Significant reflectivity Significant reflectivity of leaves of terrestrial of leaves of terrestrial planets for planets for λλ>7000>7000ÅÅ

An interesting (maybe An interesting (maybe unique) candidate for unique) candidate for a biomarker ?a biomarker ?

extrasolarextrasolar plantsplants as as a biomarker in a biomarker in extrasolar planets Seager, Ford & Turner

Reflection spectrum of leaves

Chlorophyll AChlorophyll B

extrasolar planetsastro-ph/0210277

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Vesto Melvin Slipher (1875-1969)

Discovered redshifts of “spiral nebulae” now known as galaxiesEssential contribution for Hubble’s discovery of expanding universe

“Observations of Mars in 1924 made at the Lowell Observatory: II

spectrum observations of Mars’’PASP 36(1924)261

Red-edge as a biomarker (at least) in 1924 !

Astrobiology indeed in 1924 ! Astrobiology indeed in 1924 !

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Expected daily change of the reflected light from the earth

Ford, Seager & Turner: Nature 412 (2001) 885

Assume that the earth’s reflected light is completely separated from the Sun’s flux !

TPF (Terrestrial Planet Finder) in (10～20) years from now ?

Periodic change of 10% level due to different reflectivity of land, ocean, forest, and so onCloud is the most uncertain factor: weather forecast !

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from astronomy to astrobiology ?We are in the most exciting epoch for extrasolar planet research

Just like cosmology in 1965 (Penzias and Wilson) or in 1992 (COBE)Simply 10-40 years behind ?

What if we discover more than 1000 terrestrial planets in the next decade ?

Just like cosmology in 2003 (WMAP+others) ?

How to convince ourselves of the presence of extra-terrestrial life simply from remote observations ?

Precision extrasolar planet research ?Go back to SETI after all ?Ultra-precise spectroscopy

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Let’s thank a couple of great pioneers for attracting us to this exciting field !

fighting spirit invincible

Spectroscopic search for atmospheric signature of transiting extrasolar planetsNon-trivial and amazing success of observational cosmologySo what’s next ?A naive point of view of a simple-minded cosmologist for extrasolar planet study“Evolution” of extra-solar planet scienceThe first astro-ph paper with a word “planet” in its abstractSubaru observationOn-going three projects with HDSOrbital phase and radial velocity of HD209458b in our observing runsearch for Hα absorption due to the atmosphere of HD209458bThe most stringent upper limit on the Hα absorption in the atmosphere of HD209458bSee poster B20 (Josh Winn) for detailsOther lines (preliminary results)Ask Norio Narita for detailsThe Rossiter-McLaughlin effectRadial velocity anomaly due to the Rossiter-McLaughlin effectSpectroscopic transit signature: the Rossiter-McLaughlin effectAnalytic templates for the velocity anomaly due to the Rossiter -McLaughlin effectDependence on 10 parametersFor further details, see poster B13 by Yasuhiro Ohta and Atsushi TaruyaPossible constraints on TrES-1 systemSearch for scattered light from HD209458bA possible roadmap of sciences of extrasolar planetAstrobiology ? Not yetRed edge of (extrasolar) plants: a biomarker in extrasolar planetsVesto Melvin Slipher (1875-1969)Expected daily change of the reflected light from the earthfrom astronomy to astrobiology ?Let’s thank a couple of great pioneers for attracting us to this exciting field !