We report the serendipitous detection of a very bright , very nearby microlensing event .
In late October 2006 , an otherwise unremarkable A0 star at a distance \sim 1 ~ { } { kpc } ( GSC 3656-1328 ) brightened achromatically by a factor of nearly 40 over the span of several days and then decayed in an apparently symmetrical way .
We present a light curve of the event based on optical photometry from the Center for Backyard Astrophysics and the All Sky Automated Survey , as well as near-infrared photometry from the Peters Automated Infrared Imaging Telescope .
This light curve is well-fit by a generic microlensing model .
We also report optical spectra and Swift X-ray and UV observations that are consistent with the microlensing interpretation .
We discuss and reject alternative explanations for this variability .
The lens star is probably a low-mass star or brown dwarf , with a relatively high proper motion of \gtrsim 20 ~ { } { mas~ { } yr ^ { -1 } } , and may be visible using precise optical/infrared imaging taken several years from now .
A modest , all-sky survey telescope could detect \sim 10 such events per year , which would enable searches for very low-mass planetary companions to relatively nearby stars .