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OB390 and the new microlensing planets Christian Coutures Eso Santiago September 2006 Planet searches 1 2 1 M 2 M a p -1 * Doppler wobbles: V* ~ 30ms sin i M M AU J sun Harps 1 ms1 . Timeline 20 years? rp 2 R* 2 R R J sun R a -1 * with probability Pt ~ 0.1 R sun 0.03AU f Transits : flux dimming ~ 10 -2 f 1 m p M 1 a d * 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 1/ 2 E DOL 1/ 2 1/ 2 E (mas) 2.854 M 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 (~1arcsec) 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 105 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 0.220.11 MSUN • Primary lens distance: DL = 6.6 ± 1.0 kpc • Planet mass: 5.5 M p 5.52.7 M EARTH • Planet separation: 1.5 a 2.60.6 AU • Orbital period: 8.7 P 9.02.9 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