M. Freeman

MOA-2011-BLG-293Lb: A TEST OF PURE SURVEY MICROLENSING PLANET DETECTIONS

Mathematical and Physical Sciences: 1st Place (The Ohio State University Edward F. Hayes Graduate Research Forum)

A terrestrial planet in a ~1-AU orbit around one member of a ∼15-AU binary

Impolite planet ignores hosts partner Many known exoplanets (planets outside our own solar system) are hosted by binary systems that contain two stars. These planets normally circle around both of their stars. Using microlensing data taken with a worldwide network of telescopes, Gould et al. found a planet twice the mass of Earth that circles just one of a pair of stars. The same approach has the potential to uncover other similar star systems and help to illuminate some of the mysteries of planet formation. Science, this issue p. 46 Microlensing observations reveal an exoplanet twice the mass of Earth circling just one member of a binary system. Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth’s) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet’s temperature is much lower, <60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution.

The Exoplanet Mass-Ratio Function from the MOA-II Survey: Discovery of a Break and Likely Peak at a Neptune Mass

We report the results of the statistical analysis of planetary signals discovered in MOA-II microlensing survey alert system events from 2007 to 2012. Laboratory for Exoplanets and Stellar Astrophysics, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland, New Zealand Department of Astronomy & Astrophysics, University of Chicago, 5640 S Ellis Ave, Chicago, IL 60637, USA Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi 464-8601, Japan Department of Physics, University of Auckland, Private Bag 92019, Auckland, New Zealand Okayama Astrophysical Observatory, National Astronomical Observatory, 3037-5 Honjo, Kamogata, Asakuchi, Okayama 719-0232, Japan Nagano National College of Technology, Nagano 381-8550, Japan Tokyo Metropolitan College of Industrial Technology, Tokyo 116-8523, Japan School of Chemical and Physical Sciences, Victoria University, Wellington, New Zealand Mt. John University Observatory, P.O. Box 56, Lake Tekapo 8770, New Zealand Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555, Japan Sagan Fellow, Department of Earth and Planetary Science, University of California at Berkeley, 501 Campbell Hall #3411, Berkeley, CA 94720, USA ar X iv :1 61 2. 03 93 9v 1 [ as tr oph .E P] 1 2 D ec 2 01 6

OGLE-2013-BLG-0102LA,B: MICROLENSING BINARY WITH COMPONENTS AT STAR/BROWN DWARF AND BROWN DWARF/PLANET BOUNDARIES

We present the analysis of the gravitational microlensing event OGLE-2013-BLG-0102. The light curve of the event is characterized by a strong short-term anomaly superposed on a smoothly varying lensing curve with a moderate magnification

Spitzer Observations of OGLE-2015-BLG-1212 Reveal a New Path toward Breaking Strong Microlens Degeneracies

A_{\rm max}\sim 1.5

The First Circumbinary Planet Found by Microlensing: OGLE-2007-BLG-349L(AB)c

. It is found that the event was produced by a binary lens with a mass ratio between the components of

OGLE-2012-BLG-0950Lb: THE FIRST PLANET MASS MEASUREMENT FROM ONLY MICROLENS PARALLAX AND LENS FLUX

q = 0.13

MOA-2010-BLG-353Lb: a possible Saturn revealed

and the anomaly was caused by the passage of the source trajectory over a caustic located away from the barycenter of the binary. From the analysis of the effects on the light curve due to the finite size of the source and the parallactic motion of the Earth, the physical parameters of the lens system are determined. The measured masses of the lens components are

Candidate gravitational microlensing events for future direct lens imaging

M_{1} = 0.096 \pm 0.013~M_{\odot}

MOA-2008-BLG-379Lb: A MASSIVE PLANET FROM A HIGH MAGNIFICATION EVENT WITH A FAINT SOURCE

and