Discovery of very high energy gamma-ray emission from the blazar 1ES 1727+502 with the MAGIC Telescopes

Motivated by the Costamante & Ghisellini (2002) predictions we investigated if the blazar 1ES 1727+502 (z = 0.055) is emitting very high energy(VHE, E>100GeV) rays.We observed the BL Lac object 1ES 1727+502 in stereoscopic mode with the two MAGIC telescopes during 14 nightsbetween May 6th and June 10th 2011, for a total effective observing time of 12.6 hours. For the study of the multiwavelength spectral energydistribution (SED) we use simultaneous optical R-band data from the KVA telescope, archival UV/optical and X-ray observations by instrumentsUVOT and XRT on board of the Swift satellite and high energy (HE, 0.1GeV - 100GeV) –ray data from the Fermi-LAT instrument. We detect,for the first time, VHE –ray emission from 1ES 1727+502 at a statistical significance of 5.5. The integral flux above 150 GeV is estimated tobe (2.1 ± 0.4)% of the Crab Nebula flux and the de-absorbed VHE spectrum has a photon index of (2.7 ± 0.5). No significant short-term variabilitywas found in any of the wavebands presented here. We model the SED using a one-zone synchrotron self-Compton model obtaining parameterstypical for this class of sources.