April 19, 2023 what do we know from the exo-planets?

Florian Rodler

What do we know about the exo-planets?

&How to detect direct signals

from exo-planets?

April 19, 2023 what do we know from the exo-planets?

Introduction

(1)201 confirmed planetary candidates + 14 confirmed planets found around solar-like stars and pulsars (in 175 planetary systems)

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April 19, 2023 what do we know from the exo-planets?

- RV: only minimum mass: MPlanet_min = MPlanet sini

- microlensing: estimation of planetary mass

→ companion a browndwarf (M>13 Mjup) ?

- transit + RV: i ≈ 90°.Exact mass determinationpossible: MPlanet_min = MPlanet .

Introduction

(1)201 confirmed planetary candidates + 14 confirmed planets found around solar-like stars and pulsars (in 175 planetary systems)

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April 19, 2023 what do we know from the exo-planets?

Introduction

(1)201 confirmed planetary candidates + 14 confirmed planets found around solar-like stars and pulsars (in 175 planetary systems)

exact determinationof mass needed!!!

- transit + RV: i ≈ 90°.Exact mass determinationpossible: MPlanet_min = MPlanet .

- astrometry (→ future)- transit + RV- direct imaging- reflected light (+RV)

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April 19, 2023 what do we know from the exo-planets?

Introduction

(2) Some do we know about these planets?

- Planetary masses (mostly Mplanet_min): 6 MEarth – 13 MJupiter

(most planets > 0.5 MJupiter)

- very close to host star: 0.03 – 60 AU (most planets < 0.1 AU: hot Jupiters)

0.5 AU

Hot Jupiter Mercury

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April 19, 2023 what do we know from the exo-planets?

Introduction

(2) Some parameters of the planets found:

- Planetary masses (mostly Mplanet_min): 6 MEarth – 13 MJupiter

(most planets > 0.5 MJupiter)

- very close to host star (0.03 – 6 AU)

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April 19, 2023 what do we know from the exo-planets?

Introduction

(2) Some do we know about those planets?

- Planetary masses (mostly Mplanet_min): 6 MEarth – 13 MJupiter

(most planets > 0.5 MJupiter)

- very close to host star: 0.03 – 60 AU (most planets < 0.1 AU: hot Jupiters)

- planets are heated up: radii are large (transits!)

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April 19, 2023 what do we know from the exo-planets?

Introduction

(2) Some do we know about those planets?

- Planetary masses (mostly Mplanet_min): 6 MEarth – 13 MJupiter

(most planets > 0.5 MJupiter)

- very close to host star: 0.03 – 60 AU (most planets < 0.1 AU: hot Jupiters)

- planets are heated up: radii are large (transits!)

- planetary atmospheres (transits, direct imaging, reflected light)

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April 19, 2023 what do we know from the exo-planets?

Introduction

(2) Some do we know about those planets?

- Planetary masses (mostly Mplanet_min): 6 MEarth – 13 MJupiter

(most planets > 0.5 MJupiter)

- very close to host star: 0.03 – 60 AU (most planets < 0.1 AU: hot Jupiters)

- planets are heated up: radii are large (transits!)

- planetary atmospheres (transits, direct imaging, reflected light)

"Direct methods"

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April 19, 2023 what do we know from the exo-planets?

"Direct methods“

... detecting a direct signal from the planet

(a) transits

(b) direct imaging

(c) reflected light

(d) other stuff ...

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April 19, 2023 what do we know from the exo-planets?

Transits

Atmosphere of the planet around HD 209458 (Charbonneau … 2001)-9

April 19, 2023 what do we know from the exo-planets?

TrES-1: thermal signature of atmosphere found (Charbonneau ... 2005)

Transits

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April 19, 2023 what do we know from the exo-planets?

Direct imaging

Planet 2M1207 (Chauvin ... 2005)

Star-planet flux ratio decreased- for young objects (self-lum.)- in the NIR

Close-in planets can hardly beimaged (< 0.1“)!

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April 19, 2023 what do we know from the exo-planets?

Burrows ... 2003)

wavelength (micron)

wavelength (micron)

Direct imaging

Planet 2M1207 (Chauvin ... 2005)

Star-planet flux ratio decreased- for young objects (self-lum.)- in the NIR

Close-in planets can hardly beimaged (< 0.1“)!

Flu

xF

lux

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April 19, 2023 what do we know from the exo-planets?

Reflected Light :: Motivation

Jupiter – Sun flux ratio in the visual : 1/250 000 000 (seen from

outer space)

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April 19, 2023 what do we know from the exo-planets?

Reflected Light :: Motivation

Jupiter – Sun flux ratio in the visual : 1/250 000 000 (seen from outer space)

Hot Jupiters are 100x closer: 0.05 AU

→ planet-star flux ratio ≈ 1/25 000 fora Jupiter sized planet!?

log distance from host star

0.05 0.5 5 [AU]

hot Jupiters

E J

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April 19, 2023 what do we know from the exo-planets?

Reflected light

High resolution, high S/N spectroscopyof star + planet in the visual!

→ approx. 2300 stellar absorption lines +

→ these lines reflected by the planet, BUT- Doppler shifted due to orbital motion- faint (a few times 1/10000 )

→ looking for the same pattern in the spectra: each stellar spectral line has its reflected counterpart ...

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April 19, 2023 what do we know from the exo-planets?

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schematics ...

April 19, 2023 what do we know from the exo-planets?

0.5 AU

Hot Jupiter MercuryRequirements

• bright host stars (spectroscopy!)

• hot Jupiters (periods of 3-5 days)

• and lots of data (S/N)!

Reflected light

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April 19, 2023 what do we know from the exo-planets?

What will we learn ...... once we detect reflected light?

• orbital inclination (+RV)→ exact planetary mass

• information about planetary atmosphere → input for theory!

Reflected light

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April 19, 2023 what do we know from the exo-planets?

Find planetary signature:

chi2 minimisation

→ calculate fits for K and contrast

→ best fit for planet

→ significance of detection: MC

Reflected light

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April 19, 2023 what do we know from the exo-planets?

Conclusions on direct methods

(a)transits atmospheres (VIS, IR), young and old radii moons!? i ≈ 90°

(b) direct imaging atmospheres (IR), young objects only not close to star

(c) reflected light atmospheres (VIS), old objects only very close to star bright objects

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April 19, 2023 what do we know from the exo-planets?

some stuff about Florian Rodler ...

Studies at Vienna observatory (1997 - ???), AustriaPhD student at MPIA, supervised by Martin Kürster

Topics of interest:beer & dancingatmospheres of exo planets, direct detectionspulsating starsobserving

Hobbies:hikingtravellingpainting biking tours...