Cheap space-based microlens parallaxes for high-magnification events

Abstract

We show that for high-magnification (A max ≳ 100) microlensing events, accurate microlens parallaxes can be obtained from three or fewer photometric measurements from a small telescope on a satellite in solar orbit at (AU) from Earth. This is 1-2 orders of magnitude less observing resources than are required for standard space-based parallaxes. Such microlens parallax measurements would yield accurate mass and distance measurements to the lens for all cases in which finite-source effects were observed from the ground over peak. This would include virtually all high-magnification events with detected planets and a substantial fraction of those without. Hence, it would permit accurate estimates of the Galactic distribution of planets. © 2012. The American Astronomical Society. All rights reserved.