Microlensing, « blue dot team »Jean-Philippe BeaulieuJean-Philippe Beaulieu

Collaborators/interested by a microlensing program on EUCLIDIAP : Batista, MarquetteObservatoire Toulouse : FouquéManchester : Kerins, Mao, RattenburyHeidelberg : Cassan, Grebel

ESO : Kubas

USA : Bennett, Gaudi, Gould

BLUE DOT LOGO ????BLUE DOT LOGO ????

Action item list for microlensers in 2008

Useful action already done : White paper to exoplanet task force (Bennett et al. astroph)JDEM RFI answer (Bennett, et al., )Participation to exoplanet forum (Gaudi et al.)Exoplanet task force reportEPRAT white paper (Beaulieu et al.)Another EPRAT white paper (Dominik et al.)

Being done now : Celebrating a 3 earth mass planetDiscovering more planets in 2008Next generation of ground based surveyDiscussing a microlensing program on board EUCLID

To be done shortly :Organisation of a microlensing workshop in Paris (January 2009)

“Recommendation B. II. 2 Without impacting the launch schedule of the astrometric mission cited above*, launch a Discovery-class space-based microlensing mission to determine the statistics of planetary mass and the separation of planets from their host stars as a function of stellar type and location in the galaxy, and to derive over a very large sample.

* “Recommendation B. I. a. 1 Launch and operate a space based astrometric mission capable of detecting planets down to the mass of the Earth around 60-100 nearby stars…”

Reading the Scriptures (aka exoplanet task force) :

Technology

• Ground-based 1-2m, Wide FOV Telescope – Several very similar telescopes already operating

• MOA-II• Pan-STARRS-1 - $20M

• Space-based microlensing mission– Requires almost no technology development.– Can extensively leverage other missions (Spitzer,

NextView, Ikonos, JWST)– Can use many components that are demonstrated on

orbit or flight qualified.

MPF Mission Design• 1.1-m aperture consisting of a

three-mirror anastigmat telescope feeding a 147 Mpixel HgCdTe focal plane (35 20482 arrays)

• The spacecraft bus is a near-identical copy of that used for Spitzer.

• The telescope system very similar to NextView commercial Earth-observing telescope designs.

• Detectors developed for JWST meet MPFs requirements.

• All elements are at TRL 6 or better.

• Total Cost $300M (without launch vehicle)

Property Value Units

Launch Vehicle 7920-9.5 Delta II

Orbit Inclined GEO 28.7 degrees

Mission Lifetime 4.0 years

Telescope Aperture 1.1 meters (diam.)

Field of View 0.95x0.68 degrees

Spatial Resolution 0.240 arcsec/pixel

Pointing Stability 0.048 arcsec

Focal Plane Format 145 Megapixels

Spectral Range 600-1700 nm in 3 bands

Quantum Efficiency >75%>55%

900-1400 nm700-1600 nm

Dark Current <1 e-/pixel/sec

Readout Noise <30 e-/read

PhotometricAccuracy

1% or better at J=20.5

Data Rate 50.1 Mbits/sec

Table 1: Key Space Mission RequirementsMPF Mission Requirements

Dark Energy Synergy• Space-based microlensing mission telescope requirements are

very similar to the requirements for many proposed dark energy missions.

• Combined dark energy/planet finding mission probably could be accomplished at a substantial savings.

• ADEPT, Destiny, SNAP, DUNE/SPACE/Euclid– Wide FOV, >1.1m aperture, technical specifications appear to

satisfy space-based microlensing survey specifications– DUNE/SPACE/Euclid can meet all the science goals without

modification to hardware. • Trade study:

– Observing time– Pass bands– FOV and Detectors– Orbit– Telemetry– Aperture– Optics– Pointing

Dark Energy SynergyEverything that is good for COSMIC SHEAR measurements,

is good for microlensing.

We have the same requirements, just slightly less stringent.

Everything that is good for COSMIC SHEAR measurements,

is good for microlensing.

Everything that is good for COSMIC SHEAR measurements,

is good for microlensing.

Everything that is good for COSMIC SHEAR measurements,

is good for microlensing.Everything that is good for COSMIC SHEAR measurements,

is good for microlensing.

Summary• Ground-based Next-Generation Survey: +$10M—$20M

– Complete network with a single wide FOV 1-2m telescope in SA.– Frequency of planets >M beyond the snow line. – Test planet formation theories.

• Either: Space-based Microlensing Mission: +$300M + launch– Complete census of planets with mass greater than Mars and a > 0.5 AU.– Sensitivity to all Solar System planet analogs except Mercury.– Demographics of planetary systems - tests planet formation theories.– Detect “outer” habitable zone (Mars-like orbits) where detection by imaging

is easiest.– Can find moons and free floating planets.

• Or: Joint lensing/Dark Energy Mission +$100M—$200M?• Total cost to “Exoplanet Community”: $120M—$420M

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

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.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 probesExcellent synergy Dark Energy/Microlensing

Searching for low mass extra Searching for low mass extra solar planets via microlensing.solar planets via microlensing.

Jean-Philippe Beaulieu, (PLANET/RoboNET, HOLMES)

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

Probability ~10-6

A planetary companion

Ep tqt

: 0.3 d, 20 sunE MMt

h 5.110 :Terre

d 110 3 :Jupiter

p5

p-3

tq

tq

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

Need to monitor small stars to get low mass planets.Need to monitor small stars to get low mass planets.

Sensitivity to Earths depends on source sizeSensitivity to Earths depends on source size

Hunting for planets via microlensing

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

Selecting microlensing event with good planet detection efficiency Two schools :

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

.

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

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

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

Detecting anomalies real time :

PLANET/RoboNet SITES

ESO Danish 1.54m 2003-2008

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

2 Jupiter mass planets detected microlensing (2004, 2005) : •Strong caustic•Central caustic Small fraction of M dwarfs orbited by a Jovian companion

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

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 weak Neptune planet signalOGLE-2005-BLG-169Lb : a weak Neptune planet signal

Gaudi et al., 2008, Science

• 3 bodies, 0.5 Mo, ~0.7 Mjup, ~0.3 Mjup• Triple lens, with finite source effects, parallaxe, & taking into account rotation of planets

• Ultimate nightmare for normal microlensing planet hunters.

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

• One has been giving headaches to Bennett since late 2004.

• The other one is much further down the road… (Dong et al. 2008)

Earth mass planet signal is washed out for giant source stars

Earth mass planet signal is washed out for giant source stars

DUNE-ML photometry

Earth at 1 AU ?

Monitor 2 108 stars down to J,Y,H ~22Color information ~ once a week~4 deg2 observed every ~20 min

Sensitivity to planets with a 3 months dedicated observing program : – 16 frocky rocky planets (Earth, Venus, Mars)– 580 fjupiter Jupiter planets– 120 fsat Saturne– 16 fnep Neptune planets

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

DUNE MICROLENSING PLANET SEARCHDUNE MICROLENSING PLANET SEARCH

CURRENT RESULTS

Microlensing is probing “Frozen” planets.

7 microlensing planets for 3 scenarios : • 3 Strong caustic • 2 High mag central caustic• 1 Planetary caustic

3 ~Jupiters, 1 ~5.5 Earth, 1 ~13 Earth(Probability of detecting Jupiters is ~30 times larger)Giant planets are rare, suggests 1-15 MEARTH might be common

1 system with ~0.7 Jup (2.3 AU), and ~0.3 Jup (4.6 AU)

Several planets in “stock”… modeling underway.

~Earth mass planets on ~AU orbits to be discovered soon…

Total cooperation between teams Total cooperation between teams

Indication : systems with multiple planets more common ?

CONTRIBUTION WITHIN BDT

Frozen super Earth - Earth mass planets are already accessibleMultiple planet systems with frozen ~Earth and Giant planet are accessible

Statistics about such systems in a few years

Down to frozen mars mass planet : •Monitoring very high mag events with small telescopes•Network of wide field imagers•Wide field imager in space

Habitable earth : •Wide field imager in space (recomm from exo planet task force)