A CHARACTERISTIC ORBITAL PERIOD
OF HOT JUPITERS
FROM THE WASP SURVEY
SIMON WALKER
Orbital period
Number of planets
Normalised flux
WASP-12 b
Residuals
Orbital phase
3.4 million transits inserted into the light curves of
125,304 Solar-like stars
Even
distribution in
radius and
period
Randomised
transit phase
and inclination
2.5
20
Stars
Planets
Planets
1.5
10
1.0
5
Stars / 106
2.0
15
0.5
V magnitude
9.3 ≤ V ≤ 12.8
1,429,264 stars
0.0
0
2
4
6
8
10
12
14
16
4000
3000
2000
18
V magnitude
Effective temperature / K
8000
7000
6000
5000
0.35
25
Stars
Planets
15
0.3
Planets
Stars
0.25
0.2
0.15
10
Stars / 106
Planets
20
0.1
5
0.05
0
−0.4
0.0
−0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Effective temperature
5050 ≤ Teff ≤6500
Mid F to early K
856,789 stars
J−H
1.0
0.9
−10
0.7
HJ
−5
0.6
0.5
0
0.4
0.3
5
0.2
0.1
10
−0.2
0.0
0.0
0.2
0.4
0.6
J−H
0.8
1.0
1.2
Dwarf probability
0.8
Dwarf probability
p ≥ 98%
751,486 stars
M
0
1
(
it
J)
im
el
R
h
oc
R
oc
lim
e
h
M
2
(
it
J)
0
J)
M
.5
R
he
c
o
t(
i
lim
M
0
1
(
it
J)
im
el
R
h
oc
R
oc
lim
e
h
M
2
(
it
J)
0
J)
M
.5
R
he
c
o
t(
i
lim
M
0
1
(
it
J)
im
el
R
h
oc
R
oc
lim
e
h
M
2
(
it
J)
0
J)
M
.5
R
he
c
o
t(
i
lim
Planets δ ≤ +20°
Butler et al. 2006
Planets δ ≤ +20°
Mayor et al. 2011
Planets δ ≤ +20°
Howard et al. 2012
Planets δ ≤ +20°
Number of planets per star
Kepler data
scaled
Gaussian Peak:
3.9±0.1 d
!
Gaussian width:
1.3±0.1 d
!
Power law index:
1.5±0.3
Orbital period / days
acirc for 1RJ
Ford & Rasio 2005
acirc for 2RJ
Number of planets per star
Dynamical migration
Kepler data
scaled
Orbital period / days
Disc migration
Herbst & Mundt 2005
Steven Cranmer
Disc migration
Herbst & Mundt 2005
Steven Cranmer
Summary
•
We have measured the selection effects in the WASP
survey
•
There is a pile up in the underlying distribution of hot
Jupiters at 3.9±0.1 days
•
This should be a useful constraint on migration models