Context :

Aims : To investigate the very high energy ( VHE : > 100 GeV ) \gamma -ray emission from the high-frequency peaked BL Lac 1ES 0229+200 .

Methods : Observations of 1ES 0229+200 at energies above 580 GeV were performed with the High Energy Stereoscopic System ( HESS ) in 2005 and 2006 .

Results:1ES 0229+200 is discovered by HESS to be an emitter of VHE photons .
A signal is detected at the 6.6 \sigma level in the HESS observations ( 41.8 h live time ) .
The integral flux above 580 GeV is ( 9.4 \pm 1.5 _ { stat } \pm 1.9 _ { syst } ) \times 10 ^ { -13 } cm ^ { -2 } s ^ { -1 } , corresponding to \sim 1.8 % of the flux observed from the Crab Nebula .
The data show no evidence for significant variability on any time scale .
The observed spectrum is characterized by a hard power law ( \Gamma = 2.50 \pm 0.19 _ { stat } \pm 0.10 _ { syst } ) from 500 GeV to \sim 15 TeV .

Conclusions : The high-energy range and hardness of the observed spectrum , coupled with the object ’ s relatively large redshift ( z = 0.1396 ) , enable the strongest constraints so far on the density of the Extragalactic Background Light ( EBL ) in the mid-infrared band .
Assuming that the emitted spectrum is not harder than \Gamma _ { int } \approx 1.5 , the HESS data support an EBL spectrum \propto \lambda ^ { -1 } and density close to the lower limit from source counts measured by Spitzer , confirming the previous indications from the HEGRA data of 1ES 1426+428 ( z = 0.129 ) .
Irrespective of the EBL models used , the intrinsic spectrum of 1ES 0229+200 is hard , thus locating the high-energy peak of its spectral energy distribution above a few TeV .