Many Kepler Planets Have Distant Companions

Wei Zhu (祝伟)

Canadian Institute for Theoretical Astrophysics

2019 March 6, Kepler & K2 SciCon V

Intrinsic architecture of

inner planetary System

  • 30% of Sun-like stars have Kepler planets.
  • Each system has on average 3 planets within 1 AU.
  • Fewer-planet systems are dynamically hotter.
  • Multi-planet systems are not always coplanar.
  • No Kepler dichotomy.
  • Our solar systems fits "well" in this picture.
i,~e \propto k^\alpha

Zhu et al., 2018, ApJ, 860, 101

(see Xie et al. 2016; Van Eylen et al. 2018 for e part)

Orbital eccentricity

HATNet

Kepler

Cold Jupiters

Cold Neptunes

(Data from NASA Exoplanet Archive)

Kepler

planets

(30%)

Go beyond 1 AU

~10% of Sun-like stars have cold giant planets (e.g., Cumming+08, Mayor+11)

Cold Neptunes are common

(e.g., Gould+06, Suzuki+16)

The outer companion dominates the mass and angular momentum budget

Super Earth-cold Jupiter relations

Cold Jupiters

Super Earths

22 from Kepler (triangles) + 39 from RV (squares)

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019)

Cold Jupiters

Super Earths

P({\rm CJ}|{\rm SE}) \approx 33\% {\rm ~vs.~} P({\rm CJ})=10\%

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019)

22 from Kepler (triangles) + 39 from RV (squares)

Super Earth-cold Jupiter relations

  • 1/3 of Kepler systems have cold Jupiter companions.
    • >50%, if [Fe/H]>0.

Cold Jupiters

Super Earths

P({\rm CJ}|{\rm SE}) \approx 33\% {\rm ~vs.~} P({\rm CJ})=10\%

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019)

22 from Kepler (triangles) + 39 from RV (squares)

Super Earth-cold Jupiter relations

  • 1/3 of Kepler systems have cold Jupiter companions.
    • >50%, if [Fe/H]>0.

Cold Jupiters

Super Earths

P({\rm CJ}|{\rm SE}) \approx 33\% {\rm ~vs.~} P({\rm CJ})=10\%

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019)

22 from Kepler (triangles) + 39 from RV (squares)

Super Earth-cold Jupiter relations

P({\rm SE}) = 30\%
P({\rm SE}|{\rm CJ}) = \frac{P({\rm SE})}{P({\rm CJ})} P({\rm CJ}|{\rm SE}) \approx 100\%
  • 1/3 of Kepler systems have cold Jupiter companions.
    • >50%, if [Fe/H]>0.
  • Cold Jupiters (almost) always have inner super Earth companions!

(Un)Popularity of Solar system

P({\rm no~SE,~CJ}) = [1-P({\rm SE}|{\rm CJ})] \times P({\rm CJ}) \approx 1\%

Zhu & Wu, 2018, AJ, 156, 92

  • Solar system has no super Earth (70%).
  • Solar system has a cold Jupiter (10%).

TESS discovers a super Earth in

pi Mensae system

10 M_{\rm J}\\ 3~{\rm AU}\\ e=0.6
5 M_\oplus\\ 6~{\rm d}

Huang et al., (2018)

(see also Gandolfi et al. 2018)

TESS + Gaia

  • TESS
    • 1000s of close-in small planets (e.g., Sullivan+15)
  • Gaia
    • 1000s of cold giants (Perryman+14)
  • TESS+Gaia provides ~1000 of multi-planet systems

Zhu & Wu, 2018, AJ, 156, 92

Super Earth & cold Jupiter

show strong correlations

  • Formation
    • They do not compete for building blocks.
    • Cold Jupiters require more stringent conditions.
  • Evolution

Zhu & Wu, 2018, AJ, 156, 92

(see also Zhu, 2019, ApJ, 873, 8)

1/3 of Kepler systems have cold Jupiter companions,

what about the other 2/3?

(see Miranda Herman's talk tomorrow)

HATNet

Keck

Cold Jupiters

(~10%)

Cold Neptunes

 

  • Most Kepler-like planetary systems have outer giant planets.
  • Almost all cold giant planets have inner small planets.
  • Cold planets play important roles in the formation and evolution of the inner system.

Cold giant planets:

Elephant in the room?

Kepler planets

(30%)

Zhu & Wu (2018)

Herman, Zhu, & Wu (2019)

Back-up slides

Intrinsic Architecture

{\rm inclination~dispersion~of~} \\ k{\rm -planet~system} \propto k^\alpha

Zhu, Petrovich, Wu et al., 2018

Planet-planet mutual inclinations affect the occurrence rate of planetary systems

{\rm \#~of~planetary~systems} = \frac{\rm \#~of~detected~systems}{\rm detectability~of~individual~system}

mutual inclination

Planet-planet mutual inclinations affect the occurrence rate of planetary systems

{\rm \#~of~planetary~systems} = \frac{\rm \#~of~detected~systems}{\rm detectability~of~individual~system}

Fraction of Sun-like stars with planets

  • >50% (Fressin et al. 2013; Petigura et al. 2013; Winn & Fabrycky 2015)

 

  • 30% (Zhu, Petrovich, Wu et al. 2018)

K2SciCon V

By Wei Zhu

K2SciCon V

Talk at the 2019 K2 Science Conference in Glendale CA

  • 83
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