One or more bound planets per Milky Way star from microlensing observations

  title={One or more bound planets per Milky Way star from microlensing observations},
  author={Arnaud Cassan and Daniel Kubas and Jean Philippe Beaulieu and Martin Dominik and Keith Horne and John G. Greenhill and Joachim Wambsganss and John W Menzies and A. Williams and U. G. J{\o}rgensen and Andrzej Udalski and David P. Bennett and Michael D. Albrow and Virginie Batista and St{\'e}phane Brillant and John A. R. Caldwell and Andrew A. Cole and Ch. Coutures and K. H. Cook and Stefan W. Dieters and D. Dominis Prester and Jadzia Donatowicz and P Fouqu{\'e} and K. M. Hill and N. Kains and Stephen R. Kane and Jean Baptiste Marquette and R. M. Martin and Karen Pollard and Kailash C. Sahu and Christian Vinter and D. M. Warren and B. Watson and Marta Zub and Takahiro Sumi and Michał K. Szymański and Marcin Kubiak and Radosław Poleski and Igor Soszyński and Krzysztof Ulaczyk and Grzegorz Pietrzyński and Łukasz Wyrzykowski},
Most known extrasolar planets (exoplanets) have been discovered using the radial velocity or transit methods. Both are biased towards planets that are relatively close to their parent stars, and studies find that around 17–30% (refs 4, 5) of solar-like stars host a planet. Gravitational microlensing, on the other hand, probes planets that are further away from their stars. Recently, a population of planets that are unbound or very far from their stars was discovered by microlensing. These… 
Microlensing Constraints on the Abundance of Extrasolar Planets
  • A. Cassan
  • Physics, Geology
    Proceedings of the International Astronomical Union
  • 2012
Abstract Galactic gravitational microlensing is a powerful technique to detect extrasolar planets at large orbital distances from their stars, from giant down to Earth-mass planets. We report a
Synthesizing Exoplanet Demographics from Radial Velocity and Microlensing Surveys. II. The Frequency of Planets Orbiting M Dwarfs
In contrast to radial velocity (RV) surveys, results from microlensing surveys indicate that giant planets with masses greater than the critical mass for core accretion (∼0.1 M {sub Jup}) are
The Feasibility of Directly Imaging Nearby Cold Jovian Planets with MIRI/JWST
The upcoming launch of the James Webb Space Telescope (JWST) will dramatically increase our understanding of exoplanets, particularly through direct imaging. Microlensing and radial velocity surveys
Microlensing Surveys for Exoplanets
Unlike most other planet-detection techniques, gravitational microlensing does not rely on detection of photons from either the host or the planet. Rather, planets are discovered by their
An Earth-mass planet orbiting α Centauri B
The detection of an Earth-mass planet orbiting the authors' neighbour star α Centauri B, a member of the closest stellar system to the Sun, is reported.
The Kepler space telescope has opened new vistas in exoplanet discovery space by revealing populations of Earth-sized planets that provide a new context for understanding planet formation.
A terrestrial planet in a ~1-AU orbit around one member of a ∼15-AU binary
Using gravitational 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.
Limits on Stellar Companions to Exoplanet Host Stars with Eccentric Planets
Though there are now many hundreds of confirmed exoplanets known, the binarity of exoplanet host stars is not well understood. This is particularly true of host stars that harbor a giant planet in a
Extrasolar Planetary Systems
The observational exploration of extrasolar planets or exoplanets is one of the hottest topics in modern astronomy. Over the last two decades, thousands of exoplanets have been discovered. Though
Constraining the Frequency of Free-Floating Planets from a Synthesis of Microlensing, Radial Velocity, and Direct Imaging Survey Results
A microlensing survey by Sumi et al. (2011) exhibits an overabundance of short-timescale events (STEs; t_E ~10 AU) and free-floating planets. Assuming these STEs are indeed due to planetary-mass


Unbound or distant planetary mass population detected by gravitational microlensing
  • T. K. D. P. I. A. F. C. S. A. K. J. B. Y. P. M. A. W. Sumi Kamiya Bennett Bond Abe Botzler Fukui Furusaw, T. Sumi, K. Ulaczyk
  • Physics, Geology
  • 2011
The discovery of a population of unbound or distant Jupiter-mass objects is reported, which are almost twice as common as main-sequence stars, based on two years of gravitational microlensing survey observations towards the Galactic Bulge.
Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing
The detection of a cool, sub-Neptune-mass planets may be more common than gas giant planets, as predicted by the core accretion theory, and is suggested to name OGLE-2005-BLG-390Lb, indicating a planetary mass companion to the lens star of the microlensing event.
We show that Earth-mass planets orbiting stars in the Galactic disk and bulge can be detected by monitoring microlensed stars in the Galactic bulge. The star and its planet act as a binary lens which
Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing
Two planets with masses that could not have been detected with other techniques are identified; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.
The abundance of Galactic planets from OGLE-III 2002 microlensing data
From the 389 OGLE-III 2002 observations of Galactic bulge microlensing events, we select 321 that are well described by a point-source point-lens light-curve model. From this sample we identify one
The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters
The occurrence rate of close-in planets (with orbital periods less than 50 days), based on precise Doppler measurements of 166 Sun-like stars, is reported, indicating that theoretical models of planet formation predict a deficit of planets in the domain from 5 to 30 Earth masses and with orbital periods under 50 days are in fact well populated.
Microlensing limits on numbers and orbits of extrasolar planets from the 1998–2000 OGLE events
We analyse three years (1998-2000) of Optical Gravitational Lensing Experiment (OGLE) observations of microlensing events to place limits on the abundance of planets with a planet-to-star mass ratio
Discovering Galactic planets by gravitational microlensing: magnification patterns and light curves
The current searches for microlensing events towards the galactic bulge can be used to detect planets around the lensing stars. Their effect is a short-term modulation on the smooth lightcurve
Planet Occurrence within 0.25 AU of Solar-Type Stars from Kepler
We report the distribution of planets as a function of planet radius, orbital period, and stellar effective temperature for orbital periods less than 50 days around solar-type (GK) stars. These
Detection of Planetary Transits Across a Sun-like Star.
High-precision, high-cadence photometric measurements of the star HD 209458 are reported, which is known from radial velocity measurements to have a planetary-mass companion in a close orbit and the detailed shape of the transit curve due to both the limb darkening of thestar and the finite size of the planet is clearly evident.