Details are available at http://www.aavso.org/possible-flare-star-bootis ...including a link to astrometry.net where I was able to get an astrometric calibration of the field:
http://nova.astrometry.net/user_images/tag?thumbnail_size=&sort=&calibrated=on&failed=on&query=Bootes+Flare
Being busy with other projects, I'm restraining myself from trawling through online archival databases to look for evidence of variability in either of the two candidate stars that might have hosted this flare.
Another thing to restrain myself from (for a while) is to take the 1/8th second exposure handheld image, in which the stars have the shape of a seeing disk trailed in a complicated pattern due to jitter, and see if I can get better astrometry from it than from the 2 second exposure, in which the stars have the shape of a seeing disk trailed over and over itself until it's just a blurry blob. By isolating the brightest part of each star in the 1/8th second image, it may be possible to measure the astrometric position of ? Boo to the limit allowed by seeing or pixel size rather than by handheld blurring. Speckle interferometry on the cheap! And if you're reading this and are intrigued by this idea, go ahead and try it!