MiNDSTEp differential photometry of the gravitationally lensed quasars
  WFI2033-4723 and HE0047-1756: Microlensing and a new time delay
  We present V and R photometry of the gravitationally lensed quasars
WFI2033-4723 and HE0047-1756. The data were taken by the MiNDSTEp collaboration
with the 1.54 m Danish telescope at the ESO La Silla observatory from 2008 to
2012. Differential photometry has been carried out using the image subtraction
method as implemented in the HOTPAnTS package, additionally using GALFIT for
quasar photometry. The quasar WFI2033-4723 showed brightness variations of
order 0.5 mag in V and R during the campaign. The two lensed components of
quasar HE0047-1756 varied by 0.2-0.3 mag within five years. We provide, for the
first time, an estimate of the time delay of component B with respect to A of
$\Delta t= 7.6\pm1.8$ days for this object. We also find evidence for a secular
evolution of the magnitude difference between components A and B in both
filters, which we explain as due to a long-duration microlensing event. Finally
we find that both quasars WFI2033-4723 and HE0047-1756 become bluer when
brighter, which is consistent with previous studies.
