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We present time-delay measurements for the new quadruply imaged quasar DESJ0408-5354, the first quadruply imaged quasar found in the Dark Energy Survey(DES). Our result is made possible by implementing a new observational strategyusing almost daily observations with the MPIA 2.2m telescope at La Sillaobservatory and deep exposures reaching a signal-to-noise ratio of about 1000per quasar image. This data quality allows us to catch small photometricvariations (a few mmag rms) of the quasar, acting on temporal scales muchshorter than microlensing, hence making the time delay measurement very robustagainst microlensing. In only 7 months we measure very accurately one of thetime delays in DES J0408-5354: Dt(AB) = -112.1 +- 2.1 days (1.8%) using onlythe MPIA 2.2m data. In combination with data taken with the 1.2m Euler Swisstelescope, we also measure two delays involving the D component of the systemDt(AD) = -155.5 +- 12.8 days (8.2%) and Dt(BD) = -42.4 +- 17.6 days (41%),where all the error bars include systematics. Turning these time delays intocosmological constraints will require deep HST imaging or ground-based AdaptiveOptics (AO), and information on the velocity field of the lensing galaxy.

COSMOGRAIL XVI: Time delays for the quadruply imaged quasar DES J0408-5354 with high-cadence photometric monitoring