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Identification of the Microlens in Event MACHO-LMC-20

Nitya Kallivayalil·Brian M. Patten·Massimo Marengo·Charles Alcock·Michael W. Werner·Giovanni G. Fazio
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Abstract

We report on the identification of the lens responsible for microlensing event MACHO-LMC-20. As part of a \textit{Spitzer}/IRAC program conducting mid-infrared follow-up of the MACHO Large Magellanic Cloud microlensing fields, we discovered a significant flux excess at the position of the source star for this event. These data, in combination with high resolution near-infrared \textit{Magellan}/PANIC data has allowed us to classify the lens as an early M dwarf in the thick disk of the Milky Way, at a distance of $\sim 2$ kpc. This is only the second microlens to have been identified, the first also being a M dwarf star in the disk. Together, these two events are still consistent with the expected frequency of nearby stars in the Milky Way thin and thick disks acting as lenses.

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Nitya Kallivayalil, Brian M. Patten, Massimo Marengo, Charles Alcock, Michael W. Werner, Giovanni G. Fazio. 2006-09-21. Identification of the Microlens in Event MACHO-LMC-20. https://doi.org/10.1086/510293

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