Transcript OB390 and the new microlensing planets

OB390 and the new
microlensing planets
Christian Coutures
Eso Santiago September 2006
Planet searches
1
 M p  M  2  a 1 2
*

Doppler wobbles: V* ~ 30ms -1 

 sin i



 

AU 
 M J  Msun 
1
Harps 1 ms
.
Timeline 20 years?
f
-2
Transits : flux dimming
~ 10
f
 rp 2  R 2
*


 
 


R J   Rsun 
 R   a -1
*
with probability Pt ~ 0.1 

R 
 
 sun  0.03AU
1
1






m

a

d
M
p
*

Astrometry : ang. disp *  10 -3 arc sec     





 AU   pc M J   Msun 

Direct Imaging (NACO)
Lensing: Look for planet flash of duration ~ 2
mp
MJ days.
Overview
Planets search with microlensing
PLANET network
OGLE 2005-BLG-390Lb and others
In the beginning…
Gravitational Lens
   
4GM
Rc 2
1/ 2


D

RE (UA)  2.854 M 1/ 2 D1/OL2 1 OL 
 DOS 

E


1/ 2


DOL
1/ 2
E (mas)  2.854 M1/ 2 DOL
1

D

OS 
M  0.3M sun,DOL  6 kpc,DOS  8 kpc :
RE 1.9 UA, E  0.32 mas
Lens with deflecting angle proportional to 1/u
Liebes S., 1969 American Journal of Physics 37, 103-104
Courtesy Phil Yock, Auckland
Relative proper motion Source-Lens.
tE 

E
tE
RE
v

Minor image
v
DOL
L
•
S
Major image
 4.2 mas.yr 1 (V /200km.s 1 ) (10kpc/ Dl )
tE  20 j
v   150 km s -1
QuickTime™ and a
decompressor
are needed to see this picture.
Light Curve
‘PSPL’ light curve
Impact parameter

u
E
A(u) 
1
u2  2
u u 4
2
u  1  A  1.34
1
1
2
2
1
 M  2 


D
D

200km.s


d
d


1


t E  25days..

0.1M  10kpc   Ds  
V

typical time for M* ~ 0.1 - 1 MS : 30

M*
days
MSun
1
u 1 A(u) 
u
Exotics
Distorsions :
 Parallax: earth movement
 Xallarap: mouvement of the (binary) source
 Finite size: impact parameter < Rsource (~1arcsec)
 Binary lens (caustic)
SINGLE LENS WITH FINITE SOURCE EFFECTS
3 source sizes : RS = 0.05,
0.1 and 0.2 RE
OB-05-254
(t-t0)/tE
DOUBLE LENS
Different trajectories
M1
Very different light curves !
M2
Caustic: locus of source positions where amplification is ∞
(in the plane of the lens)
QuickTime™ and a
decompressor
are needed to see this picture.
light source
Inverse ray shooting, caustics
Camera
Screen
Close/wide
q=M1 / M2=1
planetary caustics
Three configurations:
- close, intermediate, wide
Caustics:
- 1 central
- 0-2 planetary
Séparate regimes
(Erdl & Schneider 1993)
Central Caustic degeneracies
Jupiter:
d - 1/d
1/30è Jupiter:
dégénérescence q
A planetary companion
tE  20 j, M  0.3 Msun :
tp  q t E
Jupiter : q  3 10 -3  t p  1 j

Terre : q  105  t p  1.5 h
source star finite size
  0.003, 0.006, 0.013, 0.03 si M  0.3 Msun et DOS  9 kpc

Géante du clump:
Turn-off M.S.:
R 13 Rsun    6.7 as    0.013 si DOL  0.5 DOS
R  3 Rsun   1.6 as    0.006 si DOL  0.8 DOS
Lensing zone
d  0.618 - 1.618 RE
d 1.2 - 3.1 UA

a 


4

d 1.5 - 3.9 UA
Detection probability
1995 - 1998
THE HOLLYWOOD APPROACH
Gould et Loeb 1992 : « Planets in a solar-like system positioned half-way to the
Galactic center should leave a noticeable signature (magnification larger than 5
percent) on the light curve of a gravitationally lensed bulge star in about 20 percent
of the microlensing events. »
Griest & Safizadeh 1998 « We show that by focusing on high-magnification events,
the probability of detecting planets of Jupiter mass or greater in the lensing zone
[(0.6
1.6)RE] is nearly 100%, with the probability remaining high down to Saturn
masses and substantial even at 10 Earth masses. »
Two approaches :
Big survey telescope, and network of follow up telescopes (NASA, …)
Use existing telescopes, and alerts from surveys (PLANET, GMAN, MPS)
- Network of telescopes to do monitoring of on going alerts 24/24.
- Online analysis to detect anomalies real time.
- Monitoring of Bulge giants (brighter !).
“Follow the big stars !”
PLANET collaboration :
Probing Lensing Anomaly NETwork
http://planet.iap.fr
Boyden 1.5m
M. D. Albrow, J.P. Beaulieu, D. Bennett, S. Brillant, J. A. R. Caldwell, H. Calitz,
A Cassan, K. Cook, C. Coutures, M. Dominik, J. Donatowicz, D. Dominis,
P. Fouqué, J. Greenhill, K. Hill, M. Hoffman, K. Horne, U. Jorgensen,
S. Kane, D. Kubas, R. Martin, J. Menzies, P. Meintjes, K. R. Pollard,
K. C. Sahu, J. Wambsganss, A. Williams
Institut d'Astrophysique de Paris, INSU CNRS, Paris, France
Univ. of Canterbury, Dept. of Physics & Astronomy, Christchurch, New Zealand
South African Astronomical Observatory, South Africa
Boyden Observatory, Bloemfountein, South Africa
Canopus observatory, Univ. of Tasmania, Hobart, Australia
Niels Bohr Institute, Copenhagen, Denmark
Univ. of Potsdam, Potsdam, Germany
Space Telescope Science Institute, Baltimore, U.S.A.
Perth Observatory, Perth, Australia
PLANET
Probing Lensing
Anomaly NETwork
• 1995-200?
• 32 collaborators, 18 institutes, 10 countries
• 5 telescopes
• Coopération with RoboNET
( 3 robotic UK telescopes)
SITES PLANET/RoboNet
Boyden 1.5m
ESO Danish 1.54m 2003-2006+
Sutherland, SAAO 1m 1996-2006+
Boyden, 1.5m, CCD 2006+
Perth 0.6m 1996-2006+
Hobart 1m, 1996-2006+
RoboNet/Liverpool 2m, Canary 2005RoboNet Faulkes North 2m, Hawaii 2005RoboNet/Faulkes South 2m, Australia 2006 ?
Goals :
- 1 % photometry,
- Sampling 1 point/hour- Online analysis.
Followed Alerts
1993: MACHO (†1999), OGLE, EROS (†2003)
1995: MOA
Followed Alerts
OGLE
700
600
500
400
300
200
100
0
1995 1998 1999 2002 2003 2004 2005
100
90
80
70
60
50
40
30
20
10
0
M
Og
M
ER
1995
1997
1999
2001
2003
2005
PLANET DATA PROCESSING
At each site :
- Relative photometry for all stars real time
-“Planet Plotter”: real time fit & display
Data from all sites are uploaded to Paris:
RoboNet
SAAO
Boyden
ESO LS
Every day, homebase checks :
data, light curve fits, BAP,
StAndrews priorities algo,
Choose strategy, sampling, …
Alert the community if anomalies
Hobart
Perth
First successfull online prediction of anomalous event, rotating binary with parallax.
9 updates of PLANET alert.
time scale 60 days, u0=0.128, mass ratio 0.53, d0=0.718
Rotation parameters : Effective motion (-0.062 +0.052), PiE=0.14
Dominik et al., 2006 in preparation
Other planets hunters
• GMAN (Global Microlensing Alert Network): 1995 –
1999, CTIO 0.9m
• MPS (Microlensing Planet Search): 1997 - 1999, 1.9m
Mount Stromlo
• MicroFUN (Microlensing Follow-Up Network): 2003,
CTIO 1.3m, CTIO-Yale 1.0m, Wise 1.0m, Palomar 1.5m,
MDM 2.4m, LOAO 1.0m + 2 télescopes amateur
• RoboNET: 2004, Faulkes-N 2m, Liverpool 2m, (Faulkes-S
2m)
• OGLE-III EEWS: 2003
HOW about Planets ?
MB9947
At first sight, it looks like a planet…
But it is a binary 
THE PLANET THAT NEVER WAS ?
Jupiter at 4 AUs ???
A cool model

A variable source ?
Investigation on the way
PLANET 262-2003
MicroFUN
THE ZOO OF PLANET DATA
ANOMALIES PLANET 1995—2005
About 40 high magnification events sensitive to planets
Identified planets: 1 (+1)
Multiple anomalies: 3 (2 rotating binary lenses, 1 binarylens/binary-source or triple lens)
Finite source, single lens: 4
Caustic passages of finite source: 28 (of which 4 over cusps)
-- measurements of proper motion, stellar brightness profile
Weak, suspected, unclear anomalies: 27
(this pool harbours potential and likely contains some other jewels)
FINALLY A PLANET DETECTED !
MOA 2003-BLG-53/OGLE 2003-BLG-235
Best fit lens distance = 5.2 kpc
90% c.l. range is 2.3-5.4 kpc
Best fit separation = 3.0 AU
90% c.l. range is 1.3-3.1 AU
Best fit stellar mass = 0.36 M
90% c.l. range is 0.08-0.39 M
Best fit planet mass = 1.5 Mjup
90% c.l. range is 0.3-1.6 Mjup
If lens star is a 0.6 M white dwarf
Dlens = 6.1 kpc
ap = 1.8 AU
Mp = 2.5 Mjup
Bond et al., 2004, ApJ 606, L155
2003: MOA 2003-BLG-53/OGLE 2003-BLG-235
Bond et al., 2004, ApJ 606, L155
BEST FIT
(Bennett et al. 2006):
Lens distance = 5.8 kpc
Proj. separation = 3.6 AU
Stellar mass = 0.63 Msun
Planet mass = 2.6 MJUP
HST images discard that the
lens is a 0.6 Msun white
dwarf
2005 (1): OGLE 2005-BLG-071
Two models:
close binary :
d=0.758
q=6.7 10-3
wide binary :
d=1.294
q=7.1 10-3
Wide slightly favoured:
 2  22

M* ~ 0.13 Msun
DOL = 2.9 ± 1.2 kpc
0.9 MJUP
a ~ 2.3 AU
P ~ 10 yr
Subo Dong©
E
N
HST Image
1”
OGLE Field
2005 (2): OGLE 2005-BL53G-390
390 story (1)
OGLE alerts on july 11, 2005
PLANET observes from july 25
390 story(2)
Maximum on july 31st : A = 2.9
390 story(3)
another boring event …
390 story(4)
Should we drop it?
390 story(5)
?
August 10
390 story(6)
 ???
390 story(7)
!
Aug. 11th,
OGLE confirms
390 story(8)
 Yes!
390 story(9)
Yessssssssss !
indeed
390 story(10)
YESSSSSSSSSS!
A bump in the night…
A planet ?
A binary lens ?
OGLE-2005-BLG-390
Coopération : PLANET/RoboNET, OGLE, MOA-II
A TEXTBOOK MICROLENSING EVENT
(Gould & Loeb 1992, Bennett & Rhie 1996)
Data in the anomaly from : PLANET-D154, OGLE, MOA-II, PLANET-Perth
Data outside the anomaly from : PLANET/Robonet, PLANET-Hobart
PROBABILITY DENSITIES OF THE STAR AND ITS PLANET
Final Parameters
• Source distance DS = 1.05 ± 0.25 RGC (RGC=7.62 ± 0.32 kpc)
• Source star: a Galactic Bulge giant G4 III, RS = 9.6 ± 1.3 RSUN
• Primary lens mass:
0.21
M  0.220.11
MSUN
• Primary lens distance: DL = 6.6 ± 1.0 kpc
• Planet mass: 
5.5
M p  5.52.7
M EARTH
• Planet separation:
1.5
a  2.60.6
AU
• Orbital period:
8.7
P  9.02.9
years


Planet temperature and radius
• Star properties(MS):
L  0.0057 LSUN, R  0.23 RSUN, T  3320 K
• Planet properties:

Tp  T
R
1/ 4
1- A
430 a
Tp  42 K  230 C if A  0.4 (Neptune)
• Model Léger et al. (2004):

Rp  1.9 REARTH if   4.34 g cm-3 : ocean planet
Rp  1.6 REARTH if   7.74 g cm-3 : rocky planet
Detecting the lens 390L
  6.8  1.0 mas yr -1

contrast: ~4000 en J
5 ans? 35 mas
2005 (3): OGLE 2005-BLG-169
• New planet of 13 Earth masses
detected by microFUN et OGLE in a
very high amplification event (800, i.e.
7.3 mag)
• Source is a dwarf, moving ~ 8.6
mas/year
• Close-wide ambiguity (central caustic).
Comparaison fit PSPL et ESBL
Comparing the 4 planets (1)
Event
q
b
caustic
Max Amp.
source
OB03235 =
KB03053
0.0039
1.120
unique
7.6
MS
OB05071 close
0.0067
0.758
central
44
MS
OB05071 wide
0.0071
1.294
unique
dw=1.297
42
MS
OB05169 close
0.000083
0.9819
unique
dc=0.969
800
MS
OB05169 wide
0.000086
1.0198
unique
dw=1.067
806
MS
0.0000757
1.6097
planétary
2.9
RG
  22
2
  0.27
2
OB05390
Comparing the 4 planets (2)
tE
u0
*
E

DL
M*
Mp
a
K
days
RE
as
mas
mas
kpc
Msun
Mearth
AU
m s-1
yr-1
OB03235
61.5
0.133
0.53
0.55
3.3
5.8
0.63
830
4.3
44
OB05071
wide
70.9
0.0236
0.48
0.48
2.5
2.9
0.13
300
2.3
57
OB05169
wide
42.3
0.0012
0.44
1.00
8.6
2.7
0.49
13
3.4
1.1
OB05390
11.0
0.359
5.25
0.20
6.8
6.5
0.22
5.5
2.7
0.65
The core accretion model
Events caracteristic times
Do giant planets prefer long lasting events
(i.e. more massive lenses)?
PLANET detection efficiency
2006 Season
•
•
•
•
•
•
•
•
•
May1 - Aug.31 : 7 telescopes
96 alerts followed
12 high amplification, 16 medium (10-40)
5 stellar binairies , 9 anomalous
2 with variable source
52 « PSPL »
Promising events: 207, 238, 245, 265
OGLE 2006-BLG-245:
The planetary model has 2  194

2006 (1): OGLE 2006-BLG-245
Conclusion(s)
µlensing still explores ranges complementary to other methods (R.V.)
It is able to find light planets around 1 - 4 AU
Much less easy than it looked: Detection ≠ Caracterization
Photometry, sampling, fitting model(s), ambiguities
4 detections with caracterisation 
•3 central caustics: 2 with high amplification, 1 with low amplification
• 1 planetary caustic, with low amplification
=> High Amp events does not work: no simple single strategy!
2 Jupiters, 1x13.Earth, 1x5.Earth:
• Good indication that little planets may be more common than gaz giants
around M stars (30% vs 0.6%). This confirms the core accretion model.
3 long events, 1 short:
• Giant planets may be more common around bigger mass stars
Imprecision on the star-planet parameters:
• Better to wait and try to detect the lens …
END
Finding the source size
 
 t

E t E
•
Fitting the curve:
•
We can estimate the apparentangular radius of the source star from
measured derredened mags and colours of the source in a CMD:

log  (as)  3.212  0.421 (V  I)0  0.2 I0
•
Using the red giant clump in the CMD: position calibrated with the local
red giant from Hipparcos:

MI  0.23  0.03
(V  I) 1.00  0.05
0
•
Transform for the distance from the clump, as a function of (l,b)
because of the Galactic bar:


R0  7.62  0.32 kpc
0 14.41  0.09