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MAGIC detection of an increased activity from BL Lacertae at very-high-energy gamma rays

The MAGIC telescopes have observed an increase in the very-high-energy (VHE ; >100 GeV) gamma-ray flux from a position compatible with the blazar BL Lacertae (RA=22h02m43.3s Dec=+42d16m40s, J2000.0, z=0.07). The preliminary analysis of 0.76 hours of MAGIC data taken on 2019/05/03 (MJD 58606.18 to 58606.20) under zenith angle range from 46 to 53 deg and dark time conditions with the atmospheric transmission of 0.85, indicates a flux larger than 0.1 of the flux from the Crab nebula above 200 GeV, and detection significance over 6 sigma. The MAGIC observations were triggered by the flaring activity at HE gamma-rays reported by Fermi-LAT (ATel #12718), and optical observations by Astronomical Observatory of the University of Siena (ATel #12722). MAGIC observations on BL Lacertae will continue during the next days and multiwavelength observations are encouraged. The MAGIC contact persons for these observations are R. Mirzoyan (Razmik.Mirzoyan@mpp.mpg.de) and D. Dominis Prester (dijana@phy.uniri.hr) MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes located at the Canary island of La Palma, Spain, and designed to perform gamma-ray astronomy in the energy range from 50 GeV to greater than 50 TeV.

Gamma Ray ; >GeV ; TeV ; VHE ; Request for Observations ; AGN ; Blazar ; Quasar

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