Weather on the Nearest Brown Dwarfs: Resolved Simultaneous
  Multi-Wavelength Variability Monitoring of WISE J104915.57-531906.1AB
  We present two epochs of MPG/ESO 2.2m GROND simultaneous 6-band ($r'i'z'JHK$)
photometric monitoring of the closest known L/T transition brown dwarf binary
WISE J104915.57-531906.1AB. We report here the first resolved variability
monitoring of both the T0.5 and L7.5 components. We obtained 4 hours of focused
observations on the night of UT 2013-04-22, as well as 4 hours of defocused
(unresolved) observations on the night of UT 2013-04-16. We note a number of
robust trends in our light curves. The $r'$ and $i'$ light curves appear to be
anticorrelated with $z'$ and $H$ for the T0.5 component and in the unresolved
lightcurve. In the defocused dataset, $J$ appears correlated with $z'$ and $H$
and anticorrelated with $r'$ and $i'$, while in the focused dataset we measure
no variability for $J$ at the level of our photometric precision, likely due to
evolving weather phenomena. In our focused T0.5 component lightcurve, the $K$
band lightcurve displays a significant phase offset relative to both $H$ and
$z'$. We argue that the measured phase offsets are correlated with atmospheric
pressure probed at each band, as estimated from 1D atmospheric models. We also
report low-amplitude variability in $i'$ and $z'$ intrinsic to the L7.5
component.
