Direct Imaging of Exoplanets in Binary Stars

Sebastian Daemgen | 27.09.2017 Quiz

Sebastian Daemgen | 27.09.2017 State of the field: exoplanets in multiple stars 51 Eri HD 95086 HR 8799 beta Pic Ross 458

Macintosh et al. 2015 ESO/Rameau Jason Wang et al. ESO/A.-M. Lagrange et al. Burgasser et al. 2012 ROXS 42B HD 106906 GU Psc CHXR 73

Daemgen et al. 2017 Lagrange et al. 2016 Naud et al. 2014 Luhman et al. 2006 SR 12 C TYC 9486-927-1 HIP65426 Chauvin et al. 2017

2MASS/S. Murphy/ANU Kuzuhara et al. 2011

Sebastian Daemgen | 27.09.2017 State of the field: exoplanets in multiple stars 51 Eri HD 95086 HR 8799 beta Pic Ross 458

Macintosh et al. 2015 ESO/Rameau Jason Wang et al. ESO/A.-M. Lagrange et al. Burgasser et al. 2012 ROXS 42B HD 106906 GU Psc CHXR 73

Daemgen et al. 2017 Lagrange et al. 2016 Naud et al. 2014 Luhman et al. 2006 SR 12 C TYC 9486-927-1 HIP65426 Chauvin et al. 2017 ~40% direct imaging planets in stellar multiples!

2MASS/S. Murphy/ANU Kuzuhara et al. 2011

Sebastian Daemgen | 27.09.2017 State of the field: exoplanets in multiple stars →4% planets in multiples →40% at large radii/masses →few low-mass planets in close binaries →… OBSERVATIONS

PLANET FORMATION

Sebastian Daemgen | 27.09.2017 State of the field: exoplanets in multiple stars →4% planets in multiples →40% at large radii/masses →few low-mass planets in close binaries →… OBSERVATIONS

Harris et al. 2012 smaller/less massive protoplanetary disks (observed) Akeson & Jensen 2014 Daemgen et al. 2013 ? shorter disk lifetime (observed) Kraus et al. 2014 Nelson et al. 2000 disk eccentricity, induced (but warm) spirals (predicted) Artymowicz & Lubow 1994 Bruegger 2014 Kley et al. 2008

PLANET FORMATION

Sebastian Daemgen | 27.09.2017 State of the field: exoplanets in multiple stars →4% planets in multiples →40% at large radii/masses →few low-mass planets in close binaries →… OBSERVATIONS

fewer stable orbits: reduced chance of long-term stability (predicted) Holman & Wiegert 1999 Ngo et al. 2016 scattering of planets into peculiar orbits (predicted, observed?)

PLANET FORMATION

Sebastian Daemgen | 27.09.2017 State of the field: exoplanets in multiple stars

Observable direct imaging p e p planet occurrence rate s

e 5

 s .

0 3 –  ~25% of the single star value ~ 1 . 0 (Konrad & Daemgen 2017)

fewer stable orbits: reduced chance of long-term stability (predicted) Holman & Wiegert 1999 Ngo et al. 2016 scattering of planets into peculiar orbits (predicted, observed?)

PLANET FORMATION

Sebastian Daemgen | 27.09.2017 State of the field: exoplanets in multiple stars

Observable direct imaging p e p planet occurrence rate s

e 5

 s .

0 3 –  ~25% of the single star value ~ 1 . 0 (Konrad & Daemgen 2017)

fewer stable orbits: reduced chance of long-term stability (predicted) Holman & Wiegert 1999 Ngo et al. 2016 scattering of planets into peculiar orbits (predicted, observed?)

Hosts of transiting Hot Jupiters Hot Jupiter hosts have a => 2.9x increased chance of 50–2000 AU stellar companions compared to field star sample

Sebastian Daemgen | 27.09.2017 Ngo et al. 2016 State of the field: exoplanets in multiple stars →4% planets in multiples →40% at large radii/masses →few low-mass planets in close binaries →… OBSERVATIONS

fewer stable orbits: reduced chance of long-term stability (predicted) Holman & Wiegert 1999 Ngo et al. 2016 scattering of planets into peculiar orbits (predicted, observed?)

PLANET FORMATION

Sebastian Daemgen | 27.09.2017 State of the field: exoplanets in multiple stars →4% planets in multiples →40% at large radii/masses →few low-mass planets in close binaries →… OBSERVATIONS

observational bias: multiple stars change chance to find planets Wang et al. 2014 Ngo et al. 2016 selection bias: multiple stars were excluded from surveys Eggenberger & Udry 2010

fewer stable orbits: reduced chance of long-term stability (predicted) Holman & Wiegert 1999 Ngo et al. 2016 scattering of planets into peculiar orbits (predicted, observed?)

PLANET FORMATION

Sebastian Daemgen | 27.09.2017 ViBES: The Visual Binary Exoplanet Survey (Daemgen et al., in prep.)

33 visual multiples (=69 stars) • separation 0.5–5” (~50–500AU) • confirmed youth <50Myr • M0–B3 spectral type • binary star contrast < 3 mag • confirmed physical association • observations with VLT/SPHERE SPHERE/VLT

Sebastian Daemgen | 27.09.2017 ViBES: The Visual Binary Exoplanet Survey (Daemgen et al., in prep.)

Features: → Complete coverage of all binary separations* with Extreme AO imaging (*Together with SPOTS; Thalmann et al. 2014) → Characterize atmospheres compare with single star planets → Unbiased direct imaging planet occurrence rate (absolute and relative) in multiple stars

Sebastian Daemgen | 27.09.2017 ViBES: The Visual Binary Exoplanet Survey (Daemgen et al., in prep.)

Features: Objectives: Complete coverage of all binary → → How efficient is planet formation “under separations* with Extreme AO imaging stress”? (*Together with SPOTS; Thalmann et al. 2014) → Are planet characteristics (e.g., Characterize atmospheres compare → atmospheric composition) different? with single star planets → What is the dominant formation channel → Unbiased direct imaging planet occurrence of planets in binary stars? rate (absolute and relative) in multiple stars

Sebastian Daemgen | 27.09.2017 ViBES: Methods & Performance

Angular Differential Imaging

1”

Sebastian Daemgen | 27.09.2017 ViBES: Methods & Performance

“Off-Axis” Angular Differential Imaging cf. Morzinski et al. 2012

1”

Sebastian Daemgen | 27.09.2017 ViBES: Methods & Performance

“Off-Axis” Angular Differential Imaging cf. Morzinski et al. 2012

Sensitivity limit: 2–5 MJup for both stars

1”

Sebastian Daemgen | 27.09.2017 ViBES: A Preview

1“

Sebastian Daemgen | 27.09.2017 ViBES: A Preview

1“

Sebastian Daemgen | 27.09.2017 ViBES: Expected planet yield (Reggiani et al. 2016, Konrad & Daemgen 2017)

Hypothesis A truncated phase space

Hypothesis B same as singles

Hypothesis C like Hot Jupiters

Sebastian Daemgen | 27.09.2017 ViBES: Expected planet yield (Reggiani et al. 2016, Konrad & Daemgen 2017)

1% cf

Hypothesis A truncated phase space

4% cf Hypothesis B same as singles

Hypothesis C 12% cf like Hot Jupiters cf=substellar companion fraction

Sebastian Daemgen | 27.09.2017 ViBES: Expected planet yield (Reggiani et al. 2016, Konrad & Daemgen 2017)

1% cf

Hypothesis A truncated phase space

4% cf Hypothesis B same as singles

Hypothesis C 12% cf like Hot Jupiters cf=substellar companion fraction

Let ViBES decide...

Sebastian Daemgen | 27.09.2017 Summary: Direct Imaging of Exoplanets in Binary Stars

→ Number of (direct imaging) planets in multiple star systems is not negligible

→ Many open questions: dominant formation channel, occurrence rate, migration paths, … of planets in multiples?

→ ViBES: An unbiased high-contrast search and atmospheric characterization of planets in visual binary stars. We expect: → 1-8 planets around 33 multiple stars → Answers: relative planet abundance primary vs. secondary, confirm truncation paradigm, …

→ Future: combine ViBES with SPOTS/SHINE/… → continuous coverage of all binary separations: occurrence rate, mass fct., etc. as function of binary parameters

Sebastian Daemgen | 27.09.2017 Sebastian Daemgen | 27.09.2017 Sebastian Daemgen | 27.09.2017