Microlensing Planets from the Ground and Space. David Bennett University of Notre Dame. The Physics of Micro lensing. Foreground “lens” star + planet bend light of “source” star Multiple distorted images Total brightness change is observable Sensitive to planetary mass
University of Notre Dame
Target Field = Galactic Bulge
A high density of source and lens stars is required for a high microlensing rate.
A planet can be discovered when one of the lensed images approaches its projected position.
Best fit light curve simulated on an OGLE image
The OGLE 2003-BLG-235/MOA 2003-BLG-53 light curve (Bond et al, 2004). The right hand panel shows a close-up of the region of the planetary caustic. The theoretical light curves shown are the best fit planetary microlensing light curve (solid black curve indicating a mass ratio of q = 0.0039), another planetary mass binary lens light curve (green curve with q = 0.0069), and the best fit non-planetary binary lens light curve (magenta dashed curve), which has q > 0.03.
OGLE 2005-BLG-71 (Udalski, Jaroszynski, et al - OGLE & FUN. Addl’ data from MOA & PLANET).
Central caustic light curve perturbation (d = 1.3 or 1/1.3):
Additional planet discoveries by PLANET, MOA & OGLE, also in preparation
Extend the search from Jovian to Terrestrial Planets:
Escape ground-based confusion
with space-based resolution
D. Bennett, PI
E. Cheng, Deputy PI
Updated from Bennett & Rhie (2002) ApJ 574, 985
MPF in Geosynchronous Orbit
Focal Plane Concept
The spectrum of a typical reddened source star is compared to the QE curves of CCDs and Si-PIN detector arrays. The HgCdTe detectors developed for HST’s WFC3 instrument can detect twice as many photons as the most IR sensitive Si detectors (CCDs or CMOS). MPF will employ 56 HgCdTe and 14 Si-PIN detectors.
Similar Designs for Planet Finding & Dark Energy
MPF SNAP DESTINY
Wide-FOV near-IR optimized telescopes: Joint Mission?