Gijs Mulders, Ilaria Pascucci, Daniel ApaiUniversity of Arizona

An Increase in Planet Formation Efficiency around Low-Mass Stars

EOS (PI: Daniel Apai)

a NASA NexSS program

Planet Formation Efficiency

Mul

ders

et a

l. 20

15b.

Dis

k m

ass:

And

rew

s et

al.

2013

Low-Mass Stars have more planets?

How

ard

et a

l. 20

12

Johnson et al. 2007

Stellar Mass vs. Effective Temperature

Hub

er e

t al.

2014

, Dre

ssin

g &

Cha

rbon

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201

3

K2: talk by Ian Crossfield

Planet Candidates: Q1-Q16

KOIs from

Mullally et al. 2014

3. Detection efficiency

(Chr

istian

sen

et a

l. 20

15)

Transit Probability

Detection efficiency

(S/N)

Planet Occurrence

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b

Planet Radius

Distribution

Planet Period

Distribution

Planet Period Distribution (Q1-Q8)See Mulders et al. 2015a for details

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15a

Planet Radius Distribution (Q1-Q16)

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15b

Planet Radius Distribution (Q1-Q16)

Mul

ders

et a

l. 20

15b

Planet Radius Distribution (Q1-Q16)

Mul

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et a

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15b

4x

2x

Estimating Planet Heavy Element Mass

Wei

ss &

Mar

cy 2

014

Heavy element mass from Miller & Fortney 2011

Heavy Elements Mass in Planets P<50 days

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Heavy Elements <150 days

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More Efficient Migration of Disk Material?

?

The Planet Population around Low-Mass Stars from Kepler Prime

• Contains more small planets (<3 R_earth)• Contains fewer giant planets• Contains more heavy-metals• Extends closer in to their host stars

Indicates solid migration is the dominant factor in planet formation