Early Estimation of Microlensing Event Magnifications

Abstract

Gravitational microlensing events with high peak magnifications provide a much enhanced sensitivity to the detection of planets around the lens star. However, estimates of peak magnification during the early stages of an event by means of chi^2 minimization frequently involve an overprediction, making observing campaigns with strategies that rely on these predictions inefficient. I show that a rudimentary Bayesian formulation, incorporating the known statistical characteristics of a detection system, produces much more accurate predictions of peak magnification than chi^2 minimisation. Implementation of this system will allow efficient follow-up observing programs that focus solely on events that contribute to planetary abundance statistics.

Accepted by ApJ. 19 pages, incl 7 figures and 2 tables

References in corpus (4)

• OGLE-2003-BLG-262: Finite-Source Effects from a Point-Mass Lens
• Microlensing Constraints on the Frequency of Jupiter-Mass Companions: Analysis of Five Years of PLANET Photometry
• Improving the Prospects for Detecting Extrasolar Planets in Gravitational Microlensing in 2002
• Measuring Stellar Limb Darkening by Gravitational Microlensing

Cited by in corpus (5)

• An anomaly detector with immediate feedback to hunt for planets of Earth mass and below by microlensing
• Constraints on Planetary Companions in the Magnification A=256 Microlensing Event: OGLE-2003-BLG-423
• OGLE-2008-BLG-510: first automated real-time detection of a weak microlensing anomaly - brown dwarf or stellar binary?
• Parameter degeneracies and (un)predictability of gravitational microlensing events
• Disentangling the Black Hole Mass Spectrum with Photometric Microlensing Surveys