The Demographics of Wide-Separation Planets
Abstract
I begin this review by first defining what is meant by exoplanet demographics, and then motivating why we would like as broad a picture of exoplanet demographics as possible. I then outline the methodology and pitfalls to measuring exoplanet demographics in practice. I next review the methods of detecting exoplanets, focusing on the ability of these methods to detect wide separation planets. For the purposes of this review, I define wide separation as separations beyond the "snow line" of the protoplanetary disk, which is at ≃ 3 au for a sun-like star. I note that this definition is somewhat arbitrary, and the practical boundary depends on the host star mass, planet mass and radius, and detection method. I review the approximate scaling relations for the signal-to-noise ratio for the detectability of exoplanets as a function of the relevant physical parameters, including the host star properties. I provide a broad overview of what has already been learned from the transit, radial velocity, direct imaging, and microlensing methods. I outline the challenges to synthesizing the demographics using different methods and discuss some preliminary first steps in this direction. Finally, I describe future prospects for providing a nearly complete statistical census of exoplanets.
- Publication:
-
Demographics of Exoplanetary Systems, Lecture Notes of the 3rd Advanced School on Exoplanetary Science
- Pub Date:
- 2022
- DOI:
- 10.1007/978-3-030-88124-5_4
- arXiv:
- arXiv:2102.01715
- Bibcode:
- 2022ASSL..466..237G
- Keywords:
-
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 69 pages, 17 Figures. Review chapter to appear in the Lecture Notes of the 3rd Advanced School on Exoplanetary Science (Editors L. Mancini, K. Biazzo, V. Bozza, A. Sozzetti)