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Microlensing: Marching Toward a Complete Census of Cold Exoplanet Popula;on Subo Dong Ins;tute for Advanced Study Collaborators: Andy Gould (Ohio State) et al., [MicroFUN], Andrzej Udalski (Warsaw) et al., [OGLE], J.P. Beaulieu (IAP) et al., [PLANET], Ian Bond (Massey) et al, [MOA], Keith Horne (St. Andrews) et al., [RoboNET & LCGOT], Mar;n Dominik (St. Andrews) et al., [MiNDSTEp] Planet: Science, not yet solid Physics • “Almost every predic7on by theorists about planetary forma7on has been wrong.” -‐-‐ Sco? Tremaine • “All science is either physics or stamp collec7ng.” -‐-‐Ernest Rutherford Stamp Collec;ng Microlensing Planets Planetary Caus-cs (Gould & Loeb) Resonant Caus-cs (Mao & Paczynski) Central Caus-cs (Griest & Safizadeh) Beaulieu et al 2006 ~5.5 MEarth Bond et al 2004 Apeak ~ 12 ~1000 MEarth Apeak ~ 14 Gould et al 2006 ~13 MEarth Gaudi et al 2008 Apeak~ 8 ~86 MEarth Apeak ~ 290 Apeak ~ 40 ~1200 MEarth Ba;sta et al., 2011 Muraki et al., 2011 ~14 MEarth Apeak ~ 8 Apeak ~ 3 ~830 MEarth Sumi et al. 2010 ~22 MEarth Udalski et al 2005; Dong et al 2009 Apeak ~ 800 Dong et al in prep ~50 MEarth Apeak ~ 500 Pioneered by: Mao & Paczynski (1991) Survey-‐Follow-‐up: Gould & Loeb (1992) -‐-‐ Most sensi;ve to planets near rE (= θE DL ~ 3 AU) –> Jupiter at a Jupiter-‐like orbit is easiest to spot! -‐-‐ Planets across the galaxy (disk + bulge) planet lens Short ;mescale: tE = θE t planet /t E ~ µLS ~ 30days M planet / M star = q Intensive 24hr Monitoring of a Selec;ve Number of Events out of thousands of events from OGLE & MOA surveys Credit: S. Gaudi Mass ra;o q and projected separa;on d directly derived from light curve modeling Extrasolar Jupiter vs. Neptune Gaudi et al. (2002) – NO planets from 43 events well observed by PLANET collabora;on (1995-‐2000) :< ~30% Jupiter at ~1.5 -‐ 4 AU First Gould & Loeb type planet: A cool super Earth: ~5.5 MEarth, 2.6 AU, T~50K! OGLE-‐2005-‐BLG-‐390 (Beaulieu et al. 2006) Small Number sta;s;cs, but implies: Cold Neptunes Are Common! ~40% (16% -‐ 69% at 90% conf) (Gould et al. 2006) ~52% (23% -‐ 74%) (Cassan et al. 2011) Caus;cs: planetary, central & resonant d ~ 0.91, q ~ 0.013, Ba;sta et al., 2011, A&A, 529, 102 Central Caus;cs and High-‐magnifica;on Events High Magnifica;on Event [A > ~50] (Central Caus;c Perturba;on) Griest & Safizadeh 1998 • Great sensi;vity to planets at all angles over the peak (Detec;on & Exclusion); mul;-‐planet (Gaudi, et al, 1998, ApJL, 502, L33) • Rela;vely easy to monitor as the peak can be alerted in advance Planetary Detec;on Efficiency of Extremely High-‐magnifica;on Event OGLE-‐2004-‐BLG-‐343 Dong et al, 2006, ApJ, 642, 842 -‐-‐ Comments by Virginia Trimble et al, Astrophysics in 2006: “But we begin with honest apprecia-on of honest authors (ApJ 642, 842) who explain that ‘due to human error, intensive monitoring did not begin un-l 43 minutes aSer peak magnifica-on’ …” Amax ~ 3000, no planet signatures What planets could have been detected? Physical Detec;on Efficiency Dong et al, 2006, ApJ, 642, 842 Lesson Learned! 1 MJup 1 MNep 1 MEarth Amax~ 1600 Yee, J. et al, 2009, ApJ, 703, 2082 Microlensing Follow-‐Up Network (MicroFUN), led by Andy Gould (OSU) -‐-‐ The Network on Which the Sun Never Rises (the Bulge hopefully Never Sets) Z = 2.752 “It just shows that you can be a mother, you can work full-‐ ;me, and you can s;ll go out there and find planets” – Jennie McCormick, “Astronomy Magazine Grant Chris;e, Stardome, Auckland, New Zealand 0.4m telescope Berto Monard, Bronberg Obs., South Africa The most massive M-‐dwarf planet? Lens + Source Microlens Parallax + HST photometry & astrometry Discovery: Udalski, A. et al. 2005, ApJL, 628, 109 M = 0.46 ± 0.04 M Dlens = 3.2 ± 0.4 kpc Characteriza;on: Dong, S. et al. 2009, ApJ, 695, 970 Mp = 3.8 ± 0.4 MJ at 3.6 ± 0.2 AU The most massive M-‐dwarf planet? OGLE-‐2005-‐BLG-‐071Lb M = 0.46 ± 0.04 M Dlens = 3.2 ± 0.4 kpc Mp = 3.8 ± 0.4 MJ at 3.6 ± 0.2 AU "Dong, S. et al. 2009, ApJ, 695, 970 Too massive to form for M-‐dwarfs in core-‐accre;on (Laughlin 2004) Possibly poin;ng to Gravita;onal Instability (Boss 2002, 2006) More massive Jupiters around M-‐dwarfs MOA-‐2009-‐BLG-‐387Lb: Host -‐-‐ M* ~ 0.19 Msun; Planet – Mp ~ 2.6 MJ a ~ 2 AU Ba-sta et al., 2011, A&A, 529, 102 Planet Discovery for Theorists Alert Follow-‐up Planet!!! 15 But in reality … Daily New Event s Survey Groups: OGLE/MOA Anomaly/High-‐mag Alerts Anomalous? Planet? Binary? Systema;c? Real-‐;me Modeling “Homebase”: Pseudo Observers Photometry, CMD Other Follow-‐up groups (PLANET/ RoboNET/ MindSTEP) Photometry Sharing High-‐magnifica;on? Peak Mag? When? Need New Observa;ons to improve predic;on? Real-‐;me Data Reduc;on DoPHOT, DIA Observing Instruc;ons via Email, Phone, Tex;ng… High-‐res Spectra? Magellan, Keck, VLT MicroFUN Observers Pre-‐processed Images via FTP, Status report Daily Instruc;ons by 2pm Emergency Schedule Change by phone Daily CTIO SMARTS queue Observa;ons Discovery of MOA-‐2009-‐BLG-‐387Lb Jul 28, 2009, 5:23pm MOA-‐2009-‐BLG-‐408 is anomalous MOA-2009-BLG-408 15 MOA MOA (NZ) 16 Imag 17 18 5040.8 -0.1 -0.05 5041 HJD -‐ 2450000 5041.2 Best-‐fit model: mass ra;o q ~ 0.1 0 5041.4 Discovery of MOA-‐2009-‐BLG-‐387Lb MOA-‐2009-‐BLG-‐408 is a binary MOA-2009-BLG-408 MOA-2009-BLG-408 14 15 MOA (NZ) Wise (Israel) Bronberg (SA) MOA MOA WC18 BRONBERG 15 16 16 17 Binary-‐lens model verified by 18 observa;ons from Israel and 17 South Africa a few hour later. -0.1 Target dropped! -0.05 5040.8 5040.8 5041 5041 5041.2 5041.2 5041.4 5041.6 5041.4 I(MO Discovery of MOA-‐2009-‐BLG-‐387Lb 17.5 18 Jul 28, 2009, 7:27pm 18.5 5040.6 5040.8 5041 MOA-‐2009-‐BLG-‐387 is also anomalous! 5041.2 16 I(MOA) 17 18 19 5036 5038 5040 5041.4 16 I(MOA) 17 18 19 5036 5038 Cell phone Sco| Gaudi 5040 d ~ 0.98 mass ra;o q ~ 0.006 angle α ~ -‐90 80 CPUs Subo First crude model: d: 0.93, q: 0.006, α ~ -‐87 16 I(MOA) 17 18 19 5036 5038 5040 Cell phone d ~ 0.98 mass ra;o q ~ 0.006 angle α ~ -‐90 Sco| Gaudi 0.4 0.2 0 -0.2 -0.4 -0.4 -0.2 0 0.2 0.4 80 CPUs Subo First crude model: d: 0.93, q: 0.006, α ~ -‐87 Discovery of MOA-‐2009-‐BLG-‐387Lb Aug 3, 2009: caus;c entrance seen from SAAO (South Africa)! Predicted: HJD’ = 5047.222 Observa;on: HJD’ = 5047.233 More massive Jupiters around M-‐dwarfs MOA-‐2009-‐BLG-‐387Lb: Host -‐-‐ M* ~ 0.19 Msun; Planet – Mp ~ 2.6 MJ a ~ 2 AU BaBsta et al., 2011, A&A, 529, 102 2010+: more intensive near real-‐;me modeling by more people (V Bozza, C Han, etc) High-‐mag events are sensi;ve to mul;ple planets • Gaudi, et al, 1998, ApJL, 502, L33 The first Jupiter/Saturn Analog: OGLE-‐2006-‐BLG-‐109 • A scaled version of our Solar System • b: ~0.71 Jupiter Mass at ~2.3 AU c: ~0.27 Jupiter Mass at ~4.6 AU • M* ~ 0.5 M Gaudi et al. 2008, Science, 319, 927 More mul;-‐planet systems from microlensing to be announced! MicroFUN From Jennie McCormick, Farm Cove, New Zealand Fun with mul;-‐site observa;ons Credit: Grant Chris;e Terrestrial Parallax COSMOS 1490 Earth al;tude: 19110.4734 km OGLE-‐2007-‐BLG-‐224, An old thick-‐disk brown dwarf M=0.056 +/-‐ 0.004 Msun; D = 525 +/-‐ 40 pc Expected: H ~ 25.7 mag Old Thick-‐disk Brown dwarf? Gould, A., et al., 2009, ApJL, 698, L147 First Determina;on of Planet Frequency beyond the Snow Line • 13 High-‐mag Events (A > 200) during 2005-‐2008 • A “Controlled Experiment” – follow-‐up not dependent on planet recogni;on Gould, Dong, Gaudi et al., 2010, ApJ, 720, 1073 Gould, Dong, Gaudi et al., 2010, ApJ, 720, 1073 Frequency of cold giants (Neptune – Jupiter) Mass ra;o range: 6 planet out of 13 high-‐mag events From 2005-‐2008 Gould, Dong, Gaudi et al., 2010, ApJ, 720, 1073 A Basic Ques;on: What is the frequency of the Solar System??? ~15% Gould, Dong, Gaudi et al., 2010, ApJ, 720, 1073 One or more A. Cassan , D. Kubas , J.-P. Beaulieu , M. Dominik , K. Hor microlensin P. Bennett , M. D A. Williams , U. G. Jørgensen , A. Udalski Frequency of cold giants (Neptune –, JD.upiter) 1,2,3 1,8 1,2,4 1,2,25 1,9 10,11 1,5 1,12 A. Cole1,6, Ch. Coutures1,2, K. H. Cook1,15, S. Dieters1,6, D. Dominis Pr 1,2,3 1,2,4 ,J , R.Cassan Martin1,8, ,D. K.Kubas R. Pollard N. Kains1,19, S. Kane1,20, J.-B. Marquette1,2A. 1,8 ,10,11 U. G. Jørgense A., Williams M. Kubiak , R. Polesk M. Zub1,3, T. Sumi21,22, M. K. Szymański10,11 1,6 10,11,24 A. Cole , Ch. Coutures1,2, K. & Ł. Wyrzykowski Mass ra;o rN. ange: Kains1,19, S. Kane1,20, J.-B. M. Zub1,3, T. Sumi21,22, M. K. 6 planet out 3 high-‐mag e10,11,24 vents & oŁ.f 1 Wyrzykowski Most known extrasolar planets (exoplanets) have been discovered with From 2 005-‐2008 3 dete using the radial velocity1,2 or transit Botheare biased Gould, methods. Dong, Gaudi t al., towards planets that are relatively close to their parent stars, and mas 2010, ApJ, Most 720, 1known 073 extrasolar planets the radial velocity or studies find that around 17–30% (refs 4, 5) ofusing solar-like stars host a 1,2349L 6–9 towards that are relati planet. Gravitational microlensing , on the other planets hand, probes studies find that around 17–30 planets that are further away from their stars. Recently, a popu21 20. Kubas, D. et al. L giants found that fewer 33% M unbound dwarfs have a Jupiter-like planet. Gravitational microlen lation of than planets thatofare or very far from their stars was 3 planets following PLANET 390L. Astron. As planets that are further away 21 10 20. Kubas, D. et al. Limits onet add AU , and even lower limits of 18% have been planet between 1.524 giants found that fewer thanby33% of M dwarfs. These havestrategy a planets Jupiter-like discovered microlensing are at least as numerous 21. Gaudi, B. S. a1 f rom 2 002-‐2007 390L. Astron. Astrophys. 483, 29,30 lation of planets that are unbo 10 of our . These limits are compatible with measurement of analysis reported an AU , and even lower Way limits 18%we have been planet between 1.524 as the stars in the Milky . Here report a statistical 21. Gaudi, B. S.companions: et al.of Microlensin 10 discovered by microlensing . T Cassan , K ubas, B eaulieu, e t a l. z2 29,30 463–499 (2002 . These limits are compatible with our measurement of reported companions: analysis of 5 ye % for masses ranging from Saturn to 10 times Jupiter, in the same 5{2 microlensing data (gathered in 2002–07) thatas reveals theinfraction ofWay 10 z2 the stars the(2002). Milky .H 22. Einstein, A. Lens 463–499 2012, N ature, 4 81, 1 67 % for masses ranging from Saturn to 10 times Jupiter, in the same 5 orbit {2range. bound planets 0.5–10 AU (Sun–Earth distance) from stars. We 22. their Einstein, A.field. Lens-like action o Science 84 microlensing data (gathered in orbit range. z6 field. 23. Science 84, 506–507 (1 From our derived mass function, we estimate planets that within M. Sto findplanetary that 17 mass % of stars host Jupiter-mass (0.3–10 M0.5–10 where bound planets AU (Sun– J, Dominik, From our derived planetary{9 function, we estimate that within 23. Dominik, M. Stochastic distri 1 z6 galactic microle AU (that is, for a wider range of orbital separations than pre0.5210 M 5 318 M and M is Earth’s mass). Cool Neptunes (10–30 M ) find that 17 % of stars host Ju J › › › galactic microlensing events. {9 range of orbital separations than pre0.5210 AU (that is, for a widerz6 24. Cassan, A. An alt 24. Cassan, A.respecAnM alternative para Between 0 .5-‐10 A U, z6 % of stars host a ‘Jupiter’ (0.3210 M ) vious studies), on average 17 M 5 318 M and Earth’ and super-Earths (5–10 M ) are even more common: their J › › is J {9 › viousz22 studies), on average 17{9 % of stars host a ‘Jupiter’ (0.3210 MJ) Astron. Astrophy Astron. Astrophys. 491, 587–5 z22 z35 z22% of stars and super-Earths (5–10 M {29 host Neptune-like planets (10230 M ). Taking and › tive abundances per star are 52 % and 62 %. We conclude that 25. Sumi, T. et al.) Aar › % of stars host Neptune-like planets (10230 M ). Taking and5252 {29 {37 25. Sumi, T. et al. A cold Neptune › {29 z Mass ass, M(M (M ⊕) + Today: High-‐mag Events 0 0.2 0.4 0.6 Today: High-‐mag Events Planetary caus;cs: Huge Untapped Poten;al! 0 0.2 0.4 0.6 Tap the poten;al of planetary caus;c – Dump Survey + Follow-‐up • High-‐mag events: limited in number • Planetary caus;cs: Hec-c, Resource-‐intensive, Complicated selec-on bias – Pure Wide-‐Field Survey and Each Lightcurve has High cadence with 24hr con;nuous coverage! • No Human Interven;on, Perfect for sta;s;cs! • Several Orders of Magnitude larger detec;on rate. • Capable of finding Free-‐floa;ng planets. – Alterna;ve Strategy • Automa;c anomaly iden;fica;on (SIGNALMEN, Dominik et al.) Redder Bandpass is Be|er Go for small sources! Benne| & Rhie 1996 Bulge is very crowded Credit: OGLE Every Image is like HST! OGLE image with 0.5” seeing Hubble ACS HRC The Ideal Instrument: Space-‐based Wide-‐Field (IR) imager Weak Lensing for Dark Energy! WFIRST (and Euclid @ Europe) Dark Energy + Microlensing Planet + General IR survey “… WFIRST will carry out a powerful extrasolar planet search by monitoring a large sample of stars in the central bulge of the Milky Way for small devia;ons in brightness due to microlensing by intervening solar systems. This census, combined with that made by the Kepler mission, will determine how common Earth-‐like planets are over a wide range of orbital parameters. ..” Benne| et al., 2009, MPF white paper L2: Bonus point! Stamp Collec;ng Microlensing Planets Planetary Caus-cs (Gould & Loeb) Resonant Caus-cs (Mao & Paczynski) Central Caus-cs (Griest & Safizadeh) Beaulieu et al 2006 ~5.5 MEarth Bond et al 2004 Apeak ~ 12 ~1000 MEarth Apeak ~ 14 Gould et al 2006 ~13 MEarth Gaudi et al 2008 Apeak~ 8 ~86 MEarth Apeak ~ 290 Apeak ~ 40 ~1200 MEarth Ba;sta et al., 2011 Muraki et al., 2011 ~14 MEarth Apeak ~ 8 Apeak ~ 3 ~830 MEarth Sumi et al. 2010 ~22 MEarth Udalski et al 2005; Dong et al 2009 Apeak ~ 800 Dong et al in prep ~50 MEarth Apeak ~ 500 MOA-‐2009-‐BLG-‐266, Survey “1.5” ~10 Earth mass at ~3.2 AU Muraki, Y., et al., 2011, ApJ, 741, 22 Credit: S. Gaudi MOA-‐2009-‐BLG-‐266, Survey “1.5” ~10 Earth mass at ~3.2 AU Muraki, Y., et al., 2011, ApJ, 741, 22 Signal of an Earth from the ground! Next-‐Gen Search in Ac;on Now! • OGLE IV (Chile) A. Udalski et al. 15-‐45 min cadence 11 deg2 • MOA-‐II (New Zealand) I Bond et al. 15 min cadence 13 deg2 • WISE (Israel) D Maoz et al. 30 min cadence 8 deg2 Order of ~50 planets over 4 yr (Shvartzvald & Maoz, 2012, MNRAS.419.3631S) MOA-‐2011-‐BLG-‐293Lb: A testbed for pure survey microlensing planet detec;ons OGLE 15 MOA CTIO I Wise I (mag) Weizmann 16 17 18 15.0 15.5 15.5 16.0 16.0 16.5 16.5 17.0 0.2 0.3 0.4 0.5 0.6 HJD’-5747. 17.0 0.2 0.3 0.4 0.5 0.6 HJD’-5747. Point-Lens Fit Survey-Only Data 15 I (mag) 16 17 18 15.0 Planet Fit Survey-Only Data 15.0 15.0 15.5 15.5 16.0 16.0 16.5 16.5 17.0 0.2 0.3 0.4 0.5 0.6 HJD’-5747. 17.0 0.2 0.3 0.4 0.5 0.6 HJD’-5747. Point-Lens Fit All Data 5747.5 Planet Fit All Data 5748.0 HJD’ 5748.5 5747.5 5748.0 HJD’ 5748.5 Yee et al., 2012, arXiv: 1201.1002 q=5.1 +/-‐ 0.2x10-‐3 s=0.545 +/-‐ 0.005 M_L ~ 0.44 Msun m_p ~ 2.4 MJup In ~3-‐5 years • KMTNet – Three 1.6m telescope with ~4 deg2 FoV – Thousands of events per year with 10-‐20 min cadence, expected to find ~ a few dozen ηEarth and 1-‐2 orders of mag more Neptunes and Jupiters in 5-‐ yr survey • Antarc;ca? (Dome A) South Africa Chile Australia Microlensers Have a Tradi;on of Pessimism… A (Healthy?) Dose of Pessimism • “Therefore, there is no great chance of observing this phenomenon (microlensing)…” -- A. Einstein, 1936, Science, 84, 506 • “The principle was fine, but it was considered a science fiction by me as well as all other astronomers ...” -- B. Paczynski, 1994, recalling early days before any microlensing experiments ever started … • “The number of people who deserve to be acknowledged here is probably larger than the number of planets that will ever be found by microlensing.”! -- B. Scott Gaudi, PhD thesis, 2000 Thank you!