Towards Earth mass planets via Towards Earth mass planets via microlensing.microlensing.

Jean-Philippe Beaulieu, et al.HOLMES & PLANET Collaboration

Institut d’Astrophysique de Paris

Europlanet Munster

1-7 kpc from Sun

Galactic center Sun8 kpc

Light curve

Source starand images

Lens starand planet Observer

Target Field in the Central Galactic BulgeTarget Field in the Central Galactic Bulge

A planetary companionA planetary companion

Ep tqt

: 0.3 d, 20 sunE MMt

h 5.110 :Terre

d 110 3 :Jupiter

p5

p-3

tq

tq

Hunting for planets via microlensingHunting for planets via microlensing

Detecting real time microlensing event : OGLE-III and MOA 2

Selecting microlensing event with good planet detection efficiency Two schools :

- High magnification events and alerted anomalies (microFUN)- Monitoring a larger number of events (PLANET/ROBONET)

.

Networks of telescopes 24h/24: PLANET/RoboNET, microFUNAccurate photometry (Image subtraction since 2006)Real time analysis and modeling

All data, models, are shared immediately among the microlensing community.Cooperation is the way to go !

OGLE-III has an online anomaly detector (EWS)MOA-II

Detecting anomalies real time :

PLANET/RoboNPLANET/RoboN

et SITESet SITESESO Danish 1.54m 2003-2007

Sutherland, SAAO 1m 2002+Boyden, 1.5m, CCD 2006, 2007

Perth 0.6m 2002-2007+Hobart 1m, 2002-2007+Brazil 0.6m, 2007+Robonet : Liverpool 2m, Canary 2005+Faulkes North 2m, Hawaii 2006+Faulkes South 2m, Australia 2007+ Goals at each site :

- 1 % photometry, - Adapted Sampling rate - Online analysis.

Boyden 1.5m

The sun never rises on the network.

ZZZZZZZZZZZZZZZZZZZZZZZZZ……

Members of the PLANET collaboration serving Science

Real time analysis system

Data from all site uploaded to Paris every 5 min

http://planet.iap.frRoboNet

SAAOBoyden

Chile

Hobart

Perth

Brasil

Data stored in ParisModels updatedPredictionsDetection efficienciesAlert if anomalies

In Out

2 Jupiter mass planets detected microlensing (2004, 2005) :

Small fraction of M dwarfs orbited by a Jovian companion

OGLE-2005-BLG-390OGLE-2005-BLG-390Coopération : PLANET/RoboNET, OGLE-III, MOA-II

AT LAST, A TEXT BOOK MICROLENSING EVENT

Data in the anomaly from : PLANET-Danish, OGLE, MOA-II, PLANET-PerthData outside the anomaly from : PLANET/Robonet, PLANET-Hobart

Gould Loeb 1992, Bennett & Rhie 1996, …

PROBABILITY DENSITIES OF THE PROBABILITY DENSITIES OF THE STAR AND ITS PLANETSTAR AND ITS PLANET

Gould et al. 2006, MicroFUN, OGLE, RoboNet

OGLE-2005-BLG-169Lb:a cold Neptune planetOGLE-2005-BLG-169Lb:a cold Neptune planet

PLANET Detection efficiency By microlensing 1995-2006 : 2 ~Jupiters, 1 ~5.5 Earth, 1 ~13 EarthGazeous planets are rare, small planets seem to be commonSame direction as the core accretion model prediction

Beaulieu et al., 2006

Gould et al., 2006

Udalski et al., 2005Bond et al., 2004

Gaudi et al., 2008, Science

A scale ½ solar system : 0.5 Mo, ~0.7 Mjup, ~0.3 Mjup

• 3 bodies, 0.5 Mo, ~0.7 Mjup, ~0.3 Mjup at 2.3 AU, at 4.6 AU

• Triple lens, with finite source effects, parallaxe, & taking into account rotation of planets

• Ultimate nightmare for normal microlensing planet hunters.

• Great excitment for Gaudi, Bennett, Gould and Dong.

• Two other multiple systems « in stock », modeling underway.

Microlensing gives constraints on multiple planet systems.Microlensing gives constraints on multiple planet systems.

A scale ½ solar system (Sun, Jupiter, Saturn)

What about Earth mass planets ?

Microlensing of an Earth mass planet

• If planetary Einstein Ring < source star disk: planetary microlensing effect is washed out (Bennett & Rhie 1996)

•For a typical bulge giant source star, the limiting mass is ~10 M

•For a bulge, solar type main sequence star, the limiting mass is ~ 0.1 M

Earth mass planet signal is washed out for giant source stars

Earth mass planet signal is washed out for giant source stars

To get small mass planets, we need small source stars ! To get small mass planets, we need small source stars !

A small super Earth orbiting a very low mass starA small super Earth orbiting a very low mass star2007’s surprise, MOA 2007-BLG-192

VLT Adaptive optics :Light of the lens detectedFavored solution : star ~0.09 MoPlanet ~1.4 MM Confirmation underway…

Bennett et al., 2008 ApJ

Beaulieu et al., 2008

Ground-based confusion, space-based resolutionGround-based confusion, space-based resolution

• Main Sequence stars are not resolved from the ground• Systematic photometry errors for unresolved main sequence

stars cannot be overcome with deeper exposures (i.e. a large ground-based telescope).

• High Resolution + large field + 24hr duty cycle

EUCLID (ESA) & MPF (NASA)Refregier et al. 2008, proposal to ESA COSMIC VISIONBennett, et al., 2007 white paper exoplanet task forceBennett, Beaulieu, et al., 2008 JDEM RFI answer Beaulieu et al., 2008 ESA EPRAT white paper

Habitable Earth Habitable Earth &&down to Mars mass planetsdown to Mars mass planets

EUCLID-MLEUCLID-ML

Wide field imager in space

PLANET HUNTING EFFICIENCY WITH EUCLID

• Monitor 2 108 stars • Color information ~ once a week• ~4 square degrees observed every ~20 min each over period of 3

months• Sensitivity to planets with a 3 months dedicated3 months dedicated observing

program : – 16 16 frockyfrocky rocky planets (Earth, Venus, Mars) rocky planets (Earth, Venus, Mars)– 580 580 fjupiterfjupiter Jupiter planets Jupiter planets– 118 118 fsatfsat Saturn Saturn– 16 16 fnepfnep Neptune planets Neptune planets

Earth in habitable zone is feasible, but requires statistics (telescope time).The bulk of host system is M and K dwarfs

Earth in habitable zone is feasible, but requires statistics (telescope time).The bulk of host system is M and K dwarfs

Currently, we estimate that frocky ~30+ %, fJupiter ~ 5%Currently, we estimate that frocky ~30+ %, fJupiter ~ 5%

Transiting planets

microlensing

Radial velocities

Solar system : E = Earth J = Jupiter, N = Neptune…

The near-term: automated follow-upThe near-term: automated follow-up1-5 yr

Milestones: Milestones: A. An optimised planetary microlens follow-up

network, including feedback from fully-automated real-time modelling.

B. The first census of the cold planet population, involving planets of Neptune to super-Earth (few M⊕ to 20 M⊕) with host star separations around 2 AU.

C. Under highly favourable conditions, sensitivity to planets close to Earth mass with host separations around 2 AU.

Running existing facilities with existing operations Running existing facilities with existing operations

The medium-term: wide-field The medium-term: wide-field telescope networkstelescope networks

5-10 yrMilestones:Milestones:A. Complete census of the cold planet

population down to ~10 M⊕ with host separations above 1.5 AU.

B. The first census of the free-floating planet population.

C. Sensitivity to planets close to Earth mass with host separations around 2 AU.

Several existing nodes already.Several existing nodes already.Adding one node in South Africa, + operation : 10-20 M$Adding one node in South Africa, + operation : 10-20 M$

The longer-term: a space-based The longer-term: a space-based microlensing surveymicrolensing survey

10+ yr10+ yrMilestones:Milestones:A. A complete census of planets down to Earth

mass with separations exceeding 1 AUB. Complementary coverage to Kepler of the

planet discovery space.C. Potential sensitivity to planets down to 0.1

M⊕, including all Solar System analogues except for Mercury.

D. Complete lens solutions for most planet events, allowing direct measurements of the planet and host masses, projected separation and distance from the observer.

Dedicated ~400 M$, or participation to Dark energy probesDedicated ~400 M$, or participation to Dark energy probesExcellent synergy Dark Energy/MicrolensingExcellent synergy Dark Energy/Microlensing

CONCLUSIONCONCLUSION

Microlensing is today probing “Frozen” planets.

8 microlensing planets published to date :

3 ~Jupiters, 1 ~ 1.4 Earth, 1 ~5.5 Earth, 1 ~13 Earth1 multiple system : Jupiter + Saturn

(Probability of detecting Jupiters is ~30 times larger)Giant planets are rare, suggests 1-15 MEARTH might be common

Several planets in “stock”… modeling underway.Frozen ~Earth mass planets on ~AU orbits are within reach.

1- 5 yrs : automatic follow up (pointed obs) 5-10 yrs : network of wide field imagers 10+ yrs : wide field imager in space (EUCLID)

GettingGetting ηηsuper earthsuper earth, , thenthen ηη

EUCLID-MLEUCLID-ML