Sciences and Exploration Directorate

David P Bennett


David P Bennett's Contact Card & Information.
Phone: 301.286.5473
Org Code: 667
Mail Code 667
Greenbelt, MD 20771

Brief Bio

David Bennett was originally trained as a theoretical partical physicist working on the evolution of topological defects in the early universe. With Francois Bouchet, he was the first to derive the correct evolution of cosmic string networks in the early universe, and with Sun Hong Rhie, we was the first to show that global monopoles could serve as seeds for galaxy formation. With these same coauthors (and Alber Stebbins), he was the first to derive the constraints on the cosmic string, global monopole, and cosmic texture theories of galaxy formation from the COBE DMR annisotropy measurements. These constraints led to the demise of these theories.

Dr. Bennett also had a keen interest in the dark matter problem in grad school, but he was discouraged by the apparent difficulty of ruling out or confirming the least exotic dark matter theory, a Galactic halo dominated by old brown dwarf. Then, a few months before completing his PhD at Stanford, he read Bohdan Paczynski's 1986 paper on detecting brown dwarfs or MAssive Compact Halo Objects (MACHOs) in the halo using gravitational microlensing. After a postdoc in the Fermilab Theoretical Astrophysics Group (1986-1988), he had a postdoc at Princeton (1988-1990). While at Princeton, he had a chance to discuss this microlensing idea with Charles Alcock at the Lawrence Livermore National Lab, and this led to the formation of the US-Australian MACHO project that aimed to detect or rule out MACHOs (any dark objects in the planetary-stellar mass range).

In 1996, Dr. Bennett moved to a faculty position at the University of Notre Dame. In the same year, with Sun Hong Rhie, Dr. Bennett published the first general method to calculate planetary microlensing light curves including finite source effects, and they used this method to show that microlensing was sensitive to Earth-mass planets. Drs. Bennett and Rhie also formed the Microlensing Planet Search Collaboration, which was the first to demonstrate observations with the sensitivity to detect Earth-mass planets. Then, in 2000, Drs. Bennett and Rhie proposed the first wide field space telescope, the Galactic Exoplanet Survey Telescope or GEST, to survey the inner Galaxy for low-mass planets. In 2001, this concept was expanded to include a cosmological weak gravitational lensing survey, and in 2002, Drs. Bennett and Rhie published a theoretical study of the capabilities of such a  survey.

The MACHO project had largely ceased activity by 2003, and Dr. Bennett joined two new microlensing collaborations. These were the Probing Lensing Anomalies NETwork (PLANET), a follow-up program program to search for planetary signals in events identified by microlensing surveys, and the Microlensing Observations in Astrophysics (MOA), which was about to launch the first high cadence microlensing survey that would be able to detect planetary signals without follow-up observations. In 2004, the MOA collaboration led the first discovery of an extrasolar planet by the microlensing method, and in 2006, the PLANET collaboration led the discovery of the first low-mass exoplanet (~5 Earth masses). 

In 2004, Dr. Bennett led a new proposal for a space-based exoplanet microlensing survey telescope, known as the Microlensing Planet Finder (MPF). This proposal was managed by a Goddard team led by John Mather, and it employed infrared detectors instead of CCDs to help mitigate the high interstellar dust extinction seen towards the Galactic bulge. This proposal was resubmitted to the 2006 NASA Discovery competition, and resubmitted again to the Astro2010 Decadal Survey, which combined this mission concept with two other similar projects to make the Wide Field Infrared Survey Telescope (or WFIRST). WFIRST is now under development and is expected to launch in 2025.

In 2015, Dr. Bennett left the University of Notre Dame to take up his position as the leader of the gravitational microlensing group at NASA Goddard Space Flight Center. At Goddard, he has continued to work on both ground-based exoplanet microlensing surveys and WFIRST. In a 2016 paper led by former Goddard postdoc Daisuke Suzuki and Dr. Bennett, the MOA Collaboration presented a statistical study of 30 exoplanets found by microlensing. This study found that the most common cold planets have masses similar to Neptune, with planets of higher and lower masses less common. A follow-up paper, by Drs. Suzuki and Bennett with the MOA team and several theorists, argues that the microlensing results do not support the idea of runaway gas accretion in the formation of giant planets. This was thought to explain why the Solar System has no planets between the masses of Neptune and Saturn, but the microlensing study indicates that these intermediate mass giant planets are more common than Saturns and Jupiters, but less common than Neptunes.

Dr. Bennett is currently working with current postdoc Aparna Bhattacharya to characterize these planets in the Suzuki et al. (2016, 2018) sample, with high angular resolution observations from the Hubble Space Telescope and the Keck Telescope Adaptive Optics system. These observations allow precise determinations of the masses of the host star and planet, and one of the first measurements, led by Dr. Bhattacharya indicated a planet of about 40 Earth-masses, which is right in the middle of the expected gap between the masses of Neptune and Saturn. This supports the idea that the predicted mass gap does not exist.

Selected Publications


2019. "OGLE-2018-BLG-1011Lb,c: Microlensing Planetary System with Two Giant Planets Orbiting a Low-mass Star." The Astronomical Journal 158 (3): 114 [10.3847/1538-3881/ab2f74] [Journal Article/Letter]

2019. "OGLE-2015-BLG-1670Lb: A Cold Neptune beyond the Snow Line in the Provisional WFIRST Microlensing Survey Field." The Astronomical Journal 157 (6): 232 [10.3847/1538-3881/ab141b] [Journal Article/Letter]

2019. "Two new free-floating or wide-orbit planets from microlensing." Astronomy & Astrophysics 622 A201 [10.1051/0004-6361/201834557] [Journal Article/Letter]

2018. "MOA-2015-BLG-337: A Planetary System with a Low-mass Brown Dwarf/Planetary Boundary Host, or a Brown Dwarf Binary." The Astronomical Journal 156 (3): 136 [10.3847/1538-3881/aad5ee] [Journal Article/Letter]

2018. "A Planetary Microlensing Event with an Unusually Red Source Star: MOA-2011-BLG-291." The Astronomical Journal 156 (3): 113 [10.3847/1538-3881/aad59c] [Journal Article/Letter]

2018. "The First Planetary Microlensing Event with Two Microlensed Source Stars." The Astronomical Journal 155 (3): 141 [10.3847/1538-3881/aaadfa] [Journal Article/Letter]

2018. "Microlensing Results Challenge the Core Accretion Runaway Growth Scenario for Gas Giants." Astrophysical Journal Letters 869 (2): L34 [10.3847/2041-8213/aaf577] [Journal Article/Letter]

2018. "WFIRST Exoplanet Mass-measurement Method Finds a Planetary Mass of 39 ensuremathpm 8 M $_ensuremathoplus$ for OGLE-2012-BLG-0950Lb." The Astronomical Journal 156 (6): 289 [10.3847/1538-3881/aaed46] [Journal Article/Letter]

2017. "Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. VI. Age and abundance structure of the stellar populations in the central sub-kpc of the Milky Way." Astronomy & Astrophysics 605 A89 [10.1051/0004-6361/201730560] [Journal Article/Letter]

2017. "The first eclipsing binary catalogue from the MOA-II data base." Monthly Notices of the Royal Astronomical Society 470 539-550 [10.1093/mnras/stx1280] [Journal Article/Letter]

2017. "A companion on the planet/brown dwarf mass boundary on a wide orbit discovered by gravitational microlensing." Astronomy & Astrophysics 604 A103 [10.1051/0004-6361/201730928] [Journal Article/Letter]

2017. "The Star Blended with the MOA-2008-BLG-310 Source Is Not the Exoplanet Host Star." The Astronomical Journal 154 59 [10.3847/1538-3881/aa7b80] [Journal Article/Letter]

2017. "The lowest mass ratio planetary microlens: OGLE 2016-BLG-1195Lb." Monthly Notices of the Royal Astronomical Society 469 2434-2440 [10.1093/mnras/stx1049] [Journal Article/Letter]

2017. "MOA-2012-BLG-505Lb: A Super-Earth-mass Planet That Probably Resides in the Galactic Bulge." The Astronomical Journal 154 35 [10.3847/1538-3881/aa74b2] [Journal Article/Letter]

2017. "OGLE-2016-BLG-1469L: Microlensing Binary Composed of Brown Dwarfs." The Astrophysical Journal 843 59 [10.3847/1538-4357/aa740e] [Journal Article/Letter]

2017. "OGLE-2016-BLG-1003: First Resolved Caustic-crossing Binary-source Event Discovered by Second-generation Microlensing Surveys." The Astrophysical Journal 841 75 [10.3847/1538-4357/aa7057] [Journal Article/Letter]

2017. "MOA Data Reveal a New Mass, Distance, and Relative Proper Motion for Planetary System OGLE-2015-BLG-0954L." Astronomical Journal 154 68 [10.3847/1538-3881/aa7aee] [Journal Article/Letter]

2017. "Faint-source-star planetary microlensing: the discovery of the cold gas-giant planet OGLE-2014-BLG-0676Lb." Monthly Notices of the Royal Astronomical Society 466 2710-2717 [10.1093/mnras/stw3185] [Journal Article/Letter]

2017. "Binary Source Microlensing Event OGLE-2016-BLG-0733: Interpretation of a Long-term Asymmetric Perturbation." The Astronomical Journal 153 129 [10.3847/1538-3881/aa5d07] [Journal Article/Letter]

2016. "The Exoplanet Mass-ratio Function from the MOA-II Survey: Discovery of a Break and Likely Peak at a Neptune Mass." The Astrophysical Journal 833 145 [10.3847/1538-4357/833/2/145] [Journal Article/Letter]

2016. "The First Circumbinary Planet Found by Microlensing: OGLE-2007-BLG-349L(AB)c." The Astronomical Journal 152 125 [10.3847/0004-6256/152/5/125] [Journal Article/Letter]

2016. "The First Neptune Analog or Super-Earth with a Neptune-like Orbit: MOA-2013-BLG-605Lb." The Astrophysical Journal 825 (2): 112 [10.3847/0004-637x/825/2/112] [Journal Article/Letter]

2016. "A New Nonplanetary Interpretation of the Microlensing Event OGLE-2013-BLG-0723." The Astrophysical Journal 825 (1): 8 [10.3847/0004-637x/825/1/8] [Journal Article/Letter]

2016. "OGLE-2012-BLG-0724Lb: A Saturn-mass Planet around an M Dwarf." The Astrophysical Journal 824 (2): 139 [10.3847/0004-637x/824/2/139] [Journal Article/Letter]

2016. "Revisiting the Microlensing Event OGLE 2012-BLG-0026: A Solar Mass Star with Two Cold Giant Planets." The Astrophysical Journal 824 (2): 83 [10.3847/0004-637x/824/2/83] [Journal Article/Letter]

2015. "MOA-2010-BLG-353Lb: a possible Saturn revealed." Monthly Notices of the Royal Astronomical Society 454 (1): 946-951 [10.1093/mnras/stv2045] [Journal Article/Letter]

2015. "MOA-2007-BLG-197: Exploring the brown dwarf desert." Astronomy & Astrophysics 580 A125 [10.1051/0004-6361/201525791] [Journal Article/Letter]

2015. "Confirmation of the OGLE-2005-BLG-169 Planet Signature and Its Characteristics with Lens-Source Proper Motion Detection." The Astrophysical Journal 808 170 [10.1088/0004-637X/808/2/170] [Journal Article/Letter]

2015. "CONFIRMATION OF THE PLANETARY MICROLENSING SIGNAL AND STAR AND PLANET MASS DETERMINATIONS FOR EVENT OGLE-2005-BLG-169." The Astrophysical Journal 808 (2): 169 [10.1088/0004-637x/808/2/169] [Journal Article/Letter]

2015. "Pathway to the Galactic Distribution of Planets: Combined Spitzer and Ground-Based Microlens Parallax Measurements of 21 Single-Lens Events." The Astrophysical Journal 804 20 [10.1088/0004-637X/804/1/20] [Journal Article/Letter]

2015. "CAN THE MASSES OF ISOLATED PLANETARY-MASS GRAVITATIONAL LENSES BE MEASURED BY TERRESTRIAL PARALLAX?." The Astrophysical Journal 799 (2): 181 [10.1088/0004-637x/799/2/181] [Journal Article/Letter]

2014. "A terrestrial planet in a  1-AU orbit around one member of a  15-AU binary." Science 345 (6192): 46-49 [10.1126/science.1251527] [Journal Article/Letter]

2014. "MOA-2011-BLG-262Lb: A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic Bulge." The Astrophysical Journal 785 155 [10.1088/0004-637X/785/2/155] [Journal Article/Letter]

2014. "MOA-2011-BLG-293Lb: First Microlensing Planet Possibly in the Habitable Zone." The Astrophysical Journal 780 54 [10.1088/0004-637X/780/1/54] [Journal Article/Letter]

2012. "Planetary and Other Short Binary Microlensing Events from the MOA Short-event Analysis." The Astrophysical Journal 757 119 [10.1088/0004-637X/757/2/119] [Journal Article/Letter]

2012. "MOA 2010-BLG-477Lb: Constraining the Mass of a Microlensing Planet from Microlensing Parallax, Orbital Motion, and Detection of Blended Light." The Astrophysical Journal 754 73 [10.1088/0004-637X/754/1/73] [Journal Article/Letter]

2012. "A frozen super-Earth orbiting a star at the bottom of the main sequence." Astronomy & Astrophysics 540 A78 [10.1051/0004-6361/201015832] [Journal Article/Letter]

2012. "One or more bound planets per Milky Way star from microlensing observations." Nature 481 (7380): 167-169 [10.1038/nature10684] [Journal Article/Letter]

2011. "Unbound or distant planetary mass population detected by gravitational microlensing." Nature 473 (7347): 349-352 [10.1038/nature10092] [Journal Article/Letter]

2011. "MOA-2009-BLG-387Lb: a massive planet orbiting an M dwarf." Astronomy & Astrophysics 529 A102 [10.1051/0004-6361/201016111] [Journal Article/Letter]

2010. "An Efficient Method for Modeling High-magnification Planetary Microlensing Events." The Astrophysical Journal 716 1408-1422 [10.1088/0004-637X/716/2/1408] [Journal Article/Letter]

2010. "Masses and Orbital Constraints for the OGLE-2006-BLG-109Lb,c Jupiter/Saturn Analog Planetary System." The Astrophysical Journal 713 837-855 [10.1088/0004-637X/713/2/837] [Journal Article/Letter]

2008. "A Low-Mass Planet with a Possible Sub-Stellar-Mass Host in Microlensing Event MOA-2007-BLG-192." The Astrophysical Journal 684 663-683 [10.1086/589940] [Journal Article/Letter]

2008. "Detection of Extrasolar Planets by Gravitational Microlensing." Exoplanets 47-88 [10.1007/978-3-540-74008-7_3] [Article in Book]

2007. "Characterization of Gravitational Microlensing Planetary Host Stars." The Astrophysical Journal 660 781-790 [10.1086/513013] [Journal Article/Letter]

2006. "Identification of the OGLE-2003-BLG-235/MOA-2003-BLG-53 Planetary Host Star." The Astrophysical Journal 647 (2): L171-L174 [10.1086/507585] [Journal Article/Letter]

2006. "Microlens OGLE-2005-BLG-169 Implies That Cool Neptune-like Planets Are Common." The Astrophysical Journal 644 (1): L37-L40 [10.1086/505421] [Journal Article/Letter]

2006. "Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing." Nature 439 437-440 [10.1038/nature04441] [Journal Article/Letter]

2005. "Large Magellanic Cloud Microlensing Optical Depth with Imperfect Event Selection." The Astrophysical Journal 633 (2): 906-913 [10.1086/432830] [Journal Article/Letter]

2005. "Systematic Analysis of 22 Microlensing Parallax Candidates." The Astrophysical Journal 633 (2): 914-930 [10.1086/468182] [Journal Article/Letter]

2005. "Photometric Confirmation of MACHO Large Magellanic Cloud Microlensing Events." The Astrophysical Journal 631 (1): 301-311 [10.1086/432494] [Journal Article/Letter]

2005. "Determination of stellar shape in microlensing event MOA 2002-BLG-33." Astronomy & Astrophysics 439 (2): 645-650 [10.1051/0004-6361:20052858] [Journal Article/Letter]

2005. "A Jovian-Mass Planet in Microlensing Event OGLE-2005-BLG-071." The Astrophysical Journal 628 (2): L109-L112 [10.1086/432795] [Journal Article/Letter]

2004. "The Microlensing Planet Finder: completing the census of extrasolar planets in the Milky Way." Optical, Infrared, and Millimeter Space Telescopes [10.1117/12.551305] [Proceedings]

2004. "The Mass of the MACHO‐LMC‐5 Lens Star." The Astrophysical Journal 614 (1): 404-411 [10.1086/423614] [Journal Article/Letter]

2003. "Probing the atmosphere of a solar-like star by galactic microlensing at high magnification." Astronomy & Astrophysics 411 (3): L493-L496 [10.1051/0004-6361:20031602] [Journal Article/Letter]

2003. "The Galactic Exoplanet Survey Telescope (GEST)." Future EUV/UV and Visible Space Astrophysics Missions and Instrumentation [10.1117/12.459816] [Proceedings]

2002. "Gravitational Microlensing Events Due to Stellar‐Mass Black Holes." The Astrophysical Journal 579 (2): 639-659 [10.1086/342225] [Journal Article/Letter]

2002. "Simulation of a Space-based Microlensing Survey for Terrestrial Extrasolar Planets." The Astrophysical Journal 574 985-1003 [10.1086/340977] [Journal Article/Letter]

2001. "Direct detection of a microlens in the Milky Way." Nature 414 (6864): 617-619 [10.1038/414617a] [Journal Article/Letter]

2001. "The MACHO ProjectHubble Space TelescopeFollow‐Up: Preliminary Results on the Location of the Large Magellanic Cloud Microlensing Source Stars." The Astrophysical Journal 552 (2): 582-590 [10.1086/320554] [Journal Article/Letter]

2001. "MACHO Project Limits on Black Hole Dark Matter in the 1–30 [ITAL]M[/ITAL][TINF]⊙[/TINF] Range." The Astrophysical Journal 550 (2): L169-L172 [10.1086/319636] [Journal Article/Letter]

2000. "Binary Microlensing Events from the MACHO Project." The Astrophysical Journal 541 (1): 270-297 [10.1086/309393] [Journal Article/Letter]

2000. "On Planetary Companions to the MACHO 98‐BLG‐35 Microlens Star." The Astrophysical Journal 533 (1): 378-391 [10.1086/308634] [Journal Article/Letter]

1999. "Discovery of a planet orbiting a binary star system from gravitational microlensing." Nature 402 57-59 [10.1038/46990] [Journal Article/Letter]

1999. "Difference Image Analysis of Galactic Microlensing. I. Data Analysis." The Astrophysical Journal 521 602-612 [10.1086/307567] [Journal Article/Letter]

1998. "Magellanic cloud gravitational microlensing results: What do they mean?." Physics Reports 307 (1-4): 97-106 [10.1016/s0370-1573(98)00077-5] [Journal Article/Letter]

1996. "The MACHO Project: Limits on Planetary Mass Dark Matter in the Galactic Halo from Gravitational Microlensing." The Astrophysical Journal 471 (2): 774-782 [10.1086/178005] [Journal Article/Letter]

1996. "A binary lensing event toward the LMC: Observations and dark matter implications." Nuclear Physics B - Proceedings Supplements 51 (2): 152-156 [10.1016/s0920-5632(96)00497-5] [Journal Article/Letter]

1996. "Search for earth mass planets and dark matter too." Nuclear Physics B - Proceedings Supplements 51 (2): 86-90 [10.1016/s0920-5632(96)00487-2] [Journal Article/Letter]

1996. "Detecting Earth-Mass Planets with Gravitational Microlensing." The Astrophysical Journal 472 660 [10.1086/178096] [Journal Article/Letter]

1996. "The MACHO Project First-Year Large Magellanic Cloud Results: The Microlensing Rate and the Nature of the Galactic Dark Halo." The Astrophysical Journal 461 84 [10.1086/177039] [Journal Article/Letter]

1996. "Is There Evidence for Repeating Gamma-Ray Bursters in the BATSE Data?." The Astrophysical Journal 458 293 [10.1086/176812] [Journal Article/Letter]

1995. "First Observation of Parallax in a Gravitational Microlensing Event." Astrophysical Journal Letters 454 L125 [10.1086/309783] [Journal Article/Letter]

1995. "Match probability statistics and gamma-ray burst recurrences in the BATSE catalog." Astrophysics and Space Science 231 (1-2): 27-30 [10.1007/bf00658582] [Journal Article/Letter]

1995. "Probable gravitational microlensing toward the galactic bulge." The Astrophysical Journal 445 133 [10.1086/175678] [Journal Article/Letter]

1995. "Experimental Limits on the Dark Matter Halo of the Galaxy from Gravitational Microlensing." Physical Review Letters 74 (15): 2867-2871 [10.1103/physrevlett.74.2867] [Journal Article/Letter]

1994. "Possible Gravitational Microlensing Event." iaucirc 6095 1 [Journal Article/Letter]

1993. "Possible gravitational microlensing of a star in the Large Magellanic Cloud." Nature 365 (6447): 621-623 [10.1038/365621a0] [Journal Article/Letter]

1993. "COBE's constraints on the global monopole and texture theories of cosmic structure formation." The Astrophysical Journal 406 L7 [10.1086/186773] [Journal Article/Letter]

1992. "The implications of the COBE diffuse microwave radiation results for cosmic strings." The Astrophysical Journal 399 L5 [10.1086/186592] [Journal Article/Letter]

1991. "Global monopoles do not ‘‘collapse’’." Physical Review Letters 67 (9): 1173-1173 [10.1103/physrevlett.67.1173] [Journal Article/Letter]

1991. "Constraints on the gravity-wave background generated by cosmic strings." Physical Review D 43 (8): 2733-2735 [10.1103/physrevd.43.2733] [Journal Article/Letter]

1990. "Cosmological evolution of global monopoles and the origin of large-scale structure." Physical Review Letters 65 (14): 1709-1712 [10.1103/physrevlett.65.1709] [Journal Article/Letter]

1990. "High-resolution simulations of cosmic-string evolution. i. Network evolution." Physical Review D 41 (8): 2408-2433 [10.1103/physrevd.41.2408] [Journal Article/Letter]

1988. "Patterns of the cosmic microwave background from evolving string networks." Nature 335 (6189): 410-414 [10.1038/335410a0] [Journal Article/Letter]

1988. "Evidence for a Scaling Solution in Cosmic-String Evolution." Physical Review Letters 60 (4): 257-260 [10.1103/physrevlett.60.257] [Journal Article/Letter]

1986. "Evolution of cosmic strings. II." Physical Review D 34 (12): 3592-3607 [10.1103/physrevd.34.3592] [Journal Article/Letter]

1986. "Evolution of cosmic strings." Physical Review D 33 (4): 872-888 [10.1103/physrevd.33.872] [Journal Article/Letter]

1985. "Monopole-induced baryon-number violation in ‘‘realistic’’ grand unified theories." Physical Review D 31 (9): 2323-2339 [10.1103/physrevd.31.2323] [Journal Article/Letter]


2019. "Wide-Orbit Exoplanet Demographics." baas 51 (3): 505 [Report]

2018. "The WFIRST Exoplanet Microlensing Survey." arXiv e-prints arXiv:1803.08564 [Report]

2010. "Completing the Census of Exoplanets with the Microlensing Planet Finder (MPF)." ArXiv e-prints [Report]

2004. "Completing the Census of Extrasolar Planets in the Milky Way with the Microlensing Planet Finder." American Astronomical Society Meeting Abstracts 205 11.26 [Proceedings]

2003. "The Galactic Exoplanet Survey Telescope (GEST) Proposed Discovery Mission." American Astronomical Society Meeting Abstracts 203 136.03 [Proceedings]

2002. "The Galactic Exoplanet Survey Telescope: A Unique Probe of the Exoplanetary Mass Function in the Milky Way Galaxy." American Astronomical Society Meeting Abstracts 201 21.13 [Proceedings]

2001. "The Galactic Exoplanet Survey Telescope." American Astronomical Society Meeting Abstracts #198 198 69.03 [Proceedings]

2001. "Galactic Exoplanet Survey Telescope (GEST): A Proposed Space-Based Microlensing Survey for Terrestrial Extra-Solar Planets." Microlensing 2000: A New Era of Microlensing Astrophysics 239 393 [Proceedings]

2001. "Weak lensing with GEST." American Astronomical Society Meeting Abstracts 199 45.02 [Proceedings]

2000. "The Galactic Exoplanet Survey Telescope (GEST): A Search for Terrestrial Extra-solar Planets via Gravitational Microlensing." American Astronomical Society Meeting Abstracts 197 11.08 [Proceedings]

2000. "The Gravitational Microlensing Planet Search Technique from Space." AAS/Division for Planetary Sciences Meeting Abstracts #32 32 32.10 [Proceedings]

2000. "The Galactic Exoplanet Survey Telescope (GEST): A Search for Extra-Solar Planets via Gravitational Microlensing and Transits." AAS/Division for Planetary Sciences Meeting Abstracts #32 32 32.06 [Proceedings]

1991. "A search for massive compact halo objects in our galaxy." AIP Conference Proceedings [10.1063/1.40412] [Proceedings]