  Qatar-1b is a close-orbiting hot Jupiter ($R_p\simeq 1.18$ $R_J$, $M_p\simeq
1.33$ $M_J$) around a metal-rich K-dwarf, with orbital separation and period of
0.023 AU and 1.42 days. We have observed the secondary eclipse of this
exoplanet in the Ks band with the objective of deriving a brightness
temperature for the planet and providing further constraints to the orbital
configuration of the system. We obtained near-infrared photometric data from
the ground by using the OMEGA2000 instrument at the 3.5 m telescope at Calar
Alto (Spain) in staring mode, with the telescope defocused. We have used
principal component analysis (PCA) to identify correlated systematic trends in
the data. A Markov chain Monte Carlo analysis was performed to model the
correlated systematics and fit for the secondary eclipse of Qatar-1b using a
previously developed occultation model. We adopted the prayer bead method to
assess the effect of red noise on the derived parameters. We measured a
secondary eclipse depth of $0.196\%^{+0.071\%}_{-0.051\%}$, which indicates a
brightness temperature in the Ks band for the planet of $1885^{+212}_{-168}$ K.
We also measured a small deviation in the central phase of the secondary
eclipse of $-0.0079^{+0.0162}_{-0.0043}$, which leads to a value for
$e\cos{\omega}$ of $-0.0123^{+0.0252}_{-0.0067}$. However, this last result
needs to be confirmed with more data.
