Institute of Planetology and Astrophysics (IPAG · Ehrenreich & Désert (2011) • also: Lecavelier...

David EhrenreichGrenoble Institute of Planetology and Astrophysics (IPAG)

Alain Lecavelier des Etangs (IAP)David K. Sing (U Exeter)J.-M. Désert (Harvard)

Transmission spectra of exoplanet atmospheres

Primary transit

Primary transit

The planet (partially) eclipses the starTransmission spectroscopy through the limb

Chromatic variations of the optically-thick radius

∆F/F (λ) ≈ [Rp(λ)/R�]2

larger absorptions = larger radius/altitudeSeager & Sasselov (2000) • Brown (2001) • Hubbard et al. (2001) • Ehrenreich et al. (2006)

Phase

No

rmal

ised

flux

883 nm

767 nm

758 nm

679 nm

GranTeCanspectrophotometryhot jupiter XO-2bSing et al. (2011)


∆F/F (λ) ≈ [Rp(λ)/R�]2

larger absorptions = larger radius/altitudeSeager & Sasselov (2000) • Brown (2001) • Hubbard et al. (2001) • Ehrenreich et al. (2006)

GranTeCanspectrophotometryhot jupiter XO-2bSing et al. (2011)Fernandez et al. (2009)Fortney et al. (2010)

Wavelength (Å)

Pla

net

rad

ius

(RJ)


scale height

H = kBT/µg

(ΔF/F)atmo ≈ 2(ΔF/F)p (H/Rp)

Winn (2010)


scale height

H = kBT/µg


Winn (2010)

10-210-4–10-3 ~500 km


scale height

H = kBT/µg


Winn (2010)

10-510-6–10-7 ~10 km

10-210-4–10-3 ~500 km

Brighter star, better atmospheric detection

S/N ∝�F�

A background light source is required for transmission spectroscopy:

the transited star

Space- & ground-based results, from UV to NIR

• In the visible from the ground with Subaru & GranTeCan

High-resolution detection of atmospheric tracers (Na & K)

• In the visible/NIR from space with the HSTHD 209458b: temperature inversion & diffusionHD1897333b: diffusion by haze

• In the UV from space with the HSTAtmospheric evaporation of hot jupiters

• In the NIR from space with Spitzer & HST/Nicmos

Molecular composition of hot gas giants

Focus on a couple of studies

• In the visible from the ground with Subaru & GranTeCan

High-resolution detection of atmospheric tracers (Na & K)

• In the visible/NIR from space with the HSTHD 209458b: temperature inversion & diffusionHD1897333b: diffusion by haze

• In the UV from space with the HSTAtmospheric evaporation of hot jupiters

• In the NIR from space with Spitzer & HST/Nicmos

Molecular composition of hot gas giants

Charbonneau et al. (2002) • Sing et al. (2008a,b) • Snellen et al. (2008) • Lecavelier et al. (2008) • Désert et al. (2008)

Atmospheric properties of a hot jupiter

Wavelength (Å)

Ab

sorp

tio

n d

epth

(%)

Altitud

e (km)



HD 209458b HST/STIS low res

Wavelength (Å)

Ab

sorp

tio

n d

epth

(%)

Altitud

e (km)

Rayleigh scattering by H2




broad Na “plateau”

Wavelength (Å)

Ab

sorp

tio

n d

epth

(%)

Altitud

e (km)





HST/STIS med res


Wavelength (Å)

Ab

sorp

tio

n d

epth

(%)

Altitud

e (km)





HST/STIS med res


narrow Na core

Wavelength (Å)

Ab

sorp

tio

n d

epth

(%)

Altitud

e (km)

Na depletion• ionization?• condensation?





HST/STIS med res


narrow Na core

Wavelength (Å)

Ab

sorp

tio

n d

epth

(%)

Altitud

e (km)

Na depletion• ionization?• condensation?


modelTiO/VO

drivingthermal

inversion?




HST/STIS med res


narrow Na core

Wavelength (Å)

Ab

sorp

tio

n d

epth

(%)

Altitud

e (km)

Temperature inversion

2000

Sing et al. (2008a,b) • Charbonneau et al. (2002) • Snellen et al.(2008)

1500

12501000

750

500

isotherms (K)

Ab

sorp

tio

n d

epth

(%)

Altitud

e (km)

Wavelength (Å)

Vidal-Madjar et al. (2011)

Connection to the upper atmosphere

lower atmosphere T-P profilesBarman et al. 2005 • Showman et al. 2008 •Guillot 2010

upper atmosphere T-P profileYelle (2004)

10,000 Kthermosphere

EUV heating

Temperature (K)

Pre

ssur

e (b

ar)

Primary transit

The planet (partially) eclipses the star➡ Transmission spectroscopy through the limb

absorption~1%

~0.01%

Transits in HI Lyman-α (1216 Å) ➡ Exospheric studies (dynamics & composition)

absorption~1%

~10%

evaporatinghydrogen

upper atmosphere

Primary transit in the UV

Escape of light & heavy elements from HD209458b

C II lines 7.8±1.3%

Si III 1206 Å8.2±1.4%

Vidal-Madjar et al. (2003, 2004) • Linsky et al. (2010) • see also: Ehrenreich et al. (2008) • Fossati et al. (2010)

HST/COS HST/COS

HST/STIS

Wavelength (Å)

Velocity (km s-1) Velocity (km s-1)

Flux

(10-1

4 er

g c

m-2

s-1

Å-1

)Fl

ux (1

0-15

erg

cm

-2 s

-1 Å

-1)

Escape of light & heavy elements from HD209458b

C II lines 7.8±1.3%

Si III 1206 Å8.2±1.4%

Vidal-Madjar et al. (2003, 2004) • Linsky et al. (2010) • see also: Ehrenreich et al. (2008) • Fossati et al. (2010)

HST/COS HST/COS

HST/STIS

Wavelength (Å)

Velocity (km s-1) Velocity (km s-1)

Flux

(10-1

4 er

g c

m-2

s-1

Å-1

)Fl

ux (1

0-15

erg

cm

-2 s

-1 Å

-1)

➡ Hydrodynamical mass lossH flow carrying up heavier species

HST/ACS

Another case of evaporating hot jupiter: HD 189733b

Lecavelier des Etangs et al. (2010)

HST/ACS



HI Lyα 5.1±0.8%

transit in the visible is 2.4%

HST/ACS



mass-loss rate ~ 1010 g s-1

hot jupiters are stable➡ lifetime estimations

HI Lyα 5.1±0.8%

transit in the visible is 2.4%

Lifetime heating efficiency=15%

GJ436b

WASP-17b

WASP-12b

HD80606b

Kepler-10bGJ1214bCorot-7b

Kepler-9d

WASP-33b

HD189733b

HD209458b

Ehrenreich & Désert (2011) • also: Lecavelier (2007) • Davies & Wheatley (2009) • Lammer et al. (2009)

Log [Incident X/EUV energy on top of the atmosphere (erg Gyr-1)]

Log

[Gra

vita

tio

nal p

ote

ntia

l ene

rgy

(erg

)]

46 44 42 40 38 36Log(<dEEUV/dt> [erg Gyr-1])

40

41

42

43

44

45

46

47

Lo

g(-

Ep’ [

erg

])

1 Gyr

5 Gyr

10 GyrLifetime

HD80606b

< 200 pc

Atmospheric tracer (HI) absorbed by ISM ➡ nearby targets necessary!PLATO will survey 5000+ nearby M-dwarf stars bright@Lyα

Present-day transit surveys detect VIPs (mostly) at large distances

too farto monitor@Lyα

Log [Incident X/EUV energy on top of the atmosphere (erg Gyr-1)]

Log

[Gra

vita

tio

nal p

ote

ntia

l ene

rgy

(erg

)]

7

8

9

10

11

12

13

14

15 0,00 0,01 0,02 0,03 0,04 0,05

V (m

ag)

Atmospheric signal of 1 scale height (%)

Known transiting planets


Why we need P l a t o

7

8

9

10

11

12

13

14

15 0,00 0,01 0,02 0,03 0,04 0,05

V (m

ag)





3σ detection of 1 scale height by HST

7

8

9

10

11

12

13

14

15 0,00 0,01 0,02 0,03 0,04 0,05

V (m

ag)






3σ detection of 1 scale height by JWST∅/HST∅

7

8

9

10

11

12

13

14

15 0,00 0,01 0,02 0,03 0,04 0,05

V (m

ag)






3σ detection of 1 scale height by JWST∅/HST∅

PLATO planets around bright starspopulation synthesis model welcome to assess

the characterization follow-up possibilities

7

8

9

10

11

12

13

14

15 0,00 0,01 0,02 0,03 0,04 0,05

V (m

ag)





7

8

9

10

11

12

13

14

15 0,00 0,01 0,02 0,03 0,04 0,05

V (m

ag)




...and more

245,000+ stars

20,000+ stars

Why we need P l a t o3,000+ stars

Thank you!

Institute of Planetology and Astrophysics (IPAG · Ehrenreich & Désert (2011) • also: Lecavelier...

Documents

Transcript of Institute of Planetology and Astrophysics (IPAG · Ehrenreich & Désert (2011) • also: Lecavelier...