Planetesimal Disk Microlensing

Abstract

Motivated by debris disk studies, we investigate the gravitational microlensing of background starlight by a planetesimal disk around a foreground star. We use dynamical survival models to construct a plausible example of a planetesimal disk and study its microlensing properties using established ideas of microlensing by small bodies. When a solar-type source star passes behind a planetesimal disk, the microlensing light curve may exhibit short-term, low-amplitude residuals caused by planetesimals several orders of magnitude below Earth mass. The minimum planetesimal mass probed depends on the photometric sensitivity and the size of the source star, and is lower when the planetesimal lens is located closer to us. Planetesimal lenses may be found more nearby than stellar lenses because the steepness of the planetesimal mass distribution changes how the microlensing signal depends on the lens/source distance ratio. Microlensing searches for planetesimals require essentially continuous monitoring programs that are already feasible and can potentially set constraints on models of debris disks, the supposed extrasolar analogues of Kuiper belts.

15 pages, 8 figures (emulateapj). Accepted by ApJ

References in corpus (8)

• Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing
• Microlens OGLE-2005-BLG-169 Implies Cool Neptune-Like Planets are Common
• A Low-Mass Planet with a Possible Sub-Stellar-Mass Host in Microlensing Event MOA-2007-BLG-192
• Hexadecapole Approximation in Planetary Microlensing
• Disk Dispersal and Planet Formation Time Scales
• Collisional and Thermal Emission Models of Debris Disks: Towards Planetesimal Population Properties
• Microlensing Detections of Moons of Exoplanets
• Blending in Future Space-based Microlensing Surveys

Cited by in corpus (2)

• Debris Disks: Seeing Dust, Thinking of Planetesimals and Planets
• Detecting Extrasolar Asteroid Belts Through Their Microlensing Signatures