  A previously unknown optical transient (OT 120926) has been observed in the
constellation Bootes. The transient flared to magnitude 4.7, which is
comparable to the visual magnitudes of the nearby stars $\pi$ Boo and
$\omicron$ Boo. Database searches do not yield an unambiguous identification of
a quiescent counterpart of this transient but do identify several candidates.
However, none of the candidate stellar counterparts have shown any credible
evidence of previous variability in the All-Sky Automated Survey or the
Catalina Real-time Transient Survey. A flare on the nearby high proper motion,
probable M dwarf star LP 440-48 could have produced OT 120926, but the
amplitude of the flare would be an unprecedented 11.3 magnitudes. The current
record amplitude for such flares on M dwarfs is 9.5 magnitudes.
