Microlensing search for extrasolar planets from Dome C

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Microlensing search for extra-solar planets from Dome C Arnaud Cassan Astronomisches Rechen-Institut (ARI), Zentrum

Microlensing search for extra-solar planets from Dome C Arnaud Cassan Astronomisches Rechen-Institut (ARI), Zentrum für Astronomie der Universität Heidelberg (ZAH) J. -P. Beaulieu, P. Fouqué, J. -B. Marquette, C. Coutures Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Outline 1/ The microlensing method 2/ The current observing setup 3/ Results and capabilities

Outline 1/ The microlensing method 2/ The current observing setup 3/ Results and capabilities of the method 4/ Why observing from Dome C ? 5/ Summary & conclusion Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

The Gravitational microlensing effect • Probing the Galactic Halo (MACHO, EROS) • Galactic structure

The Gravitational microlensing effect • Probing the Galactic Halo (MACHO, EROS) • Galactic structure (OGLE, MACHO, EROS) • Search for extra-solar planets (PLANET, MOA, Micro. Fun) ► Magnification of the source star flux Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Observations toward the Bulge Probability of a microlensing event : 10 -6 observations toward

Observations toward the Bulge Probability of a microlensing event : 10 -6 observations toward the Bulge OGLE fields Dome C is definitely the best site to observe the Bulge from Earth Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

 • Image separation : unresolved images ! Flux magnification monitoring • Einstein radius

• Image separation : unresolved images ! Flux magnification monitoring • Einstein radius crossing time : 3 - 4 weeks continuous observations from Dome C • Maximum amplification : Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

The « standard » multi-site setup: a network of telescopes • Ongoing microlensing events

The « standard » multi-site setup: a network of telescopes • Ongoing microlensing events alerted by OGLE, MOA (EROS, MACHO) • Follow-up network : PLANET collaboration Days Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Observational strategy Observatories Raw data Data reduction pipeline BUT requires many ( on-line reduction

Observational strategy Observatories Raw data Data reduction pipeline BUT requires many ( on-line reduction ) “manual” operations… One site allow much more automated procedures, from data reduction to data analysis and modeling - Arnaud Cassan ARI / ZAH Heidelberg ”Homebase” : light curves modeling observational strategy public alerts anomaly predictions Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

MOA 2003 -BLG-53 Lb : a Jupiter-like planet Arnaud Cassan ARI / ZAH Heidelberg

MOA 2003 -BLG-53 Lb : a Jupiter-like planet Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

OGLE-2005 -BLG-071 Lb : another Jupiter-like planet Arnaud Cassan ARI / ZAH Heidelberg Optical

OGLE-2005 -BLG-071 Lb : another Jupiter-like planet Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

OGLE-2005 -BLG-390 Lb a 5. 5 Earth-mass planet Arnaud Cassan ARI / ZAH Heidelberg

OGLE-2005 -BLG-390 Lb a 5. 5 Earth-mass planet Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

OGLE-2005 -BLG-169 Lb : a weak Neptune plant signal Gaps in the coverage difficulties

OGLE-2005 -BLG-169 Lb : a weak Neptune plant signal Gaps in the coverage difficulties in modeling and finding a unique model Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Detection efficiencies [1] Modeling of individual events, e. g. : Cassan et al. ,

Detection efficiencies [1] Modeling of individual events, e. g. : Cassan et al. , 2006, en préparation [2] Statistical combination of the individual efficiencies Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Microlensing detection efficiencies 1995 - 2006 These planets of few Earth masses and few

Microlensing detection efficiencies 1995 - 2006 These planets of few Earth masses and few AU orbits may be very common A continuous monitoring from Dome C Cassan et al. , 2006, en préparation would push the detection efficiency limits toward low-mass stars Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Limits on abundance of exoplanets Ultimately, microlensing can provide a good estimation of Galactic

Limits on abundance of exoplanets Ultimately, microlensing can provide a good estimation of Galactic planet abundance Gaudi et al. 2000 • No strong selection with star brightness (only the lens mass is involved) • The « whole » range of star mass is probed Arnaud Cassan ARI / ZAH Heidelberg (prop. to their abundance) Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Multiple planetary systems Ex. Constraints on additional Jupiter-like planets on OGLE-2005 -BLG-390 Kubas, Cassan

Multiple planetary systems Ex. Constraints on additional Jupiter-like planets on OGLE-2005 -BLG-390 Kubas, Cassan et al. (in preparation) Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Complementary to other methods Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field

Complementary to other methods Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Main goals of microlensing • Detection of Neptune to Earth-mass planets • Abundance of

Main goals of microlensing • Detection of Neptune to Earth-mass planets • Abundance of extra-solar planets in the Galaxy From space simulations (MPF satellite, Bennett et al. 2005) : – 66 terrestrial planets – 100 icy giants – 3300 gas giants Order of magnitude of what may be expected from Dome C Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Why Dome C ? With he current setup : – Gaps in the light

Why Dome C ? With he current setup : – Gaps in the light curve – Multi-site photometry = difficulties with combining data sets from different telescopes (mean seeing/air mass, weather conditions, CCDs…) – Australia do not provide stable weather conditions to operate a deep round-the-clock monitoring Only 1 terrestrial planet so far Given that : - theoretical efficiency is higher than is achievable now - the main difficulties come from - the non-continuous monitorin - The weather conditions - the statistical point of view is the most relevant for microlensing search for exoplanets ► The ground base detection capabilities have been reached ► Dome C is the most relevant site to achieve the ultimate goal of microlensing searches for exoplanets = statistical aspect Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

What would Dome C provide for microlensing towards the Bulge ? • Continuous monitoring

What would Dome C provide for microlensing towards the Bulge ? • Continuous monitoring of the Bulge • Stable weather condition eliminate false alerts • Stable and good seeing, low background • One telescope with one instrument high improvement of photometry precision + known systematic errors Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

A possible setup • A 2 m-class telescope • 28 k x 28 k

A possible setup • A 2 m-class telescope • 28 k x 28 k camera 0. 09”/pixel -> 0. 5 deg 2 FOV FWHM 0. 25’’ • 2 deg 2 monitored in the Bulge • Time Sampling : every 20 min • During Antarctica winter season: in 2005 (sun < -18 deg) -> 81 days • 3 – 4 weeks continuous observations (time scale < 30 d) • A OGLE-like alert + following setup Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Summary & Conclusion • 4 extra-solar planets discovered : – 2 Jupiter-like + 1

Summary & Conclusion • 4 extra-solar planets discovered : – 2 Jupiter-like + 1 Neptune planets (2003 -2006) – A 5. 5 Earth-mass planet (2006) • Abundance of exoplanets around M-dwarfs – will ultimately extend to “all” stars • Sensitivity/limits on multi-planetary systems • Complementary to other techniques (ex. RV) • Dome C is the only site on Earth that allows a continuous monitoring of the Galactic Bulge • A realistic project : – Experience from an ongoing project (10 years with PLANET) – Expertise of data reduction/image subtraction technique – Expertise in modeling, statistical analysis Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP,

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

The single lens case Magnification curves u Einstein ring radius: Magnification: (t-t 0)/t. E

The single lens case Magnification curves u Einstein ring radius: Magnification: (t-t 0)/t. E Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Model predictions vs. microlensing observation Cassan & kubas (in preparation) OGLE 2005 -BLG-390 Lb

Model predictions vs. microlensing observation Cassan & kubas (in preparation) OGLE 2005 -BLG-390 Lb Ida & Lin, 2005, Ap. J 246, 1045 Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Crowded fields Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in

Crowded fields Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Galactic microlensing Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in

Galactic microlensing Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP,

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

OGLE 2005 -BLG-390 Lb : a cool 5. 5 Earth-mass planet 10. 8. 05

OGLE 2005 -BLG-390 Lb : a cool 5. 5 Earth-mass planet 10. 8. 05 31. 7. 05 Beaulieu et al. , 2006, Nature 439, 437 Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP,

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

What we know from the unique modeling • Planet/star mass ratio : q =

What we know from the unique modeling • Planet/star mass ratio : q = mp / M* = (7. 6 ± 0. 7) x 10 -5 • Instantaneous separation/Re : d = rphys / RE = 1. 61 ± 0. 01 • Source star distance : DS = 8. 5 kpc • Einstein ring crossing time : t. E = 11. 0 ± 0. 1 days RE = vt t. E = 1/c [ 4 GM*DL(1 -DL/DS) ]1/2 Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

The mass of OGLE 2005 -BLG-390 Lb Arnaud Cassan ARI / ZAH Heidelberg Optical

The mass of OGLE 2005 -BLG-390 Lb Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP,

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP,

Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Deriving physical parameters • Planet mass & orbit : mp = 5. 5 +5.

Deriving physical parameters • Planet mass & orbit : mp = 5. 5 +5. 5 -2. 7 Earth-mass ap = 2. 6 +1. 5 -0. 6 AU • Host star : M* = 0. 2 +0. 2 -0. 1 Msol • Lens distance : DL = 6. 6 ± 1 kpc Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Détection des exoplanètes Juillet 2003 Mai 2005 (Planète jovienne) Bond et al. , 2004,

Détection des exoplanètes Juillet 2003 Mai 2005 (Planète jovienne) Bond et al. , 2004, Ap. J 606 Arnaud Cassan ARI / ZAH Heidelberg Udalski et al. , 2005, Ap. J 628 Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

Microlentilles doubles : caustiques et courbes critiques Courbes critiques (plan-lentille) Séparation : Arnaud Cassan

Microlentilles doubles : caustiques et courbes critiques Courbes critiques (plan-lentille) Séparation : Arnaud Cassan ARI / ZAH Heidelberg Caustiques (plan-source) intermédiaire grande faible Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

The microlensing effect lens plane source plane Image < mas Source Observer Arnaud Cassan

The microlensing effect lens plane source plane Image < mas Source Observer Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006

The PLANET collaboration (Probing Lensing Anomalies NETwork) M. D. Albrow, J. P. Beaulieu, D.

The PLANET collaboration (Probing Lensing Anomalies NETwork) 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 ARI Heidelberg (Germany), IAP Paris (France), Univ. of Notre Dame (USA), Univ. of Canterbury (New Zealand), SAAO (South Africa), Boyden Observatory (South Africa), Canopus Observatory (Tasmania), Niels Bohr Institute (Denmark), Univ. of Potsdam (Germany), STSI (USA), Perth Observatory (Australia), ESO (Chile), OMP (France) Arnaud Cassan ARI / ZAH Heidelberg Optical and Infrared Wide-Field Astronomy in Antarctica IAP, 14 – 16 June 2006