Finding Planets via Gravitational Microlensing

  • Virginie BatistaEmail author
Reference work entry


Gravitational microlensing is a technique to probe compact objects toward the center of the galaxy, such as distant stars, planets, white and brown dwarfs, black holes, and neutron stars. Since the first microlensing planet discovered in 2003, more than 40 planets have been detected with this technique, as well as several black hole candidates, and a population of potential free-floating planets. This chapter first provides a presentation of the microlensing theory, including numerical aspects to solve binary and triple lens problems, and a discussion of the microlensing planetary detection efficiency, with a high potential regarding cold planets beyond the snow line. It also explains how the planetary characterization can be facilitated when the microlensing light curves exhibit distortions due to second-order effects, such as parallax, planetary orbital motion, and extended source, and how they can also introduce degeneracies in the models. The chapter then reviews the main discoveries to date and the recent statistical results from high-cadence ground-based surveys and space-based observations, especially on the planet mass function and the distance distribution of the microlensing planetary systems. Finally, future prospects are discussed, with the expected advances from dedicated space missions, extending the planet sensitivity range down to Mercury masses.


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Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Institut d’astrophysique de ParisParisFrance
  2. 2.Centre National d’Etudes SpatialesParis Cedex 1France

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