RT Journal Article T1 MAGIC observations of MWC 656, the only known Be/BH system A1 Antoranz Canales, Pedro A1 Barrio Uña, Juan Abel A1 Bonnefoy, Simon Francois Albert A1 Carreto Fidalgo, David Friedrich A1 Contreras González, José Luis A1 Fonseca González, María Victoria A1 López Moya, Marcos A1 Miranda Pantoja, José Miguel A1 Satalecka, Konstanzja A1 Scapin, Valeria AB Context. MWC 656 has recently been established as the first observationally detected high-mass X-ray binary system containing a Be star and a black hole (BH). The system has been associated with a gamma-ray flaring event detected by the AGILE satellite in July 2010.Aims. Our aim is to evaluate if the MWC 656 gamma-ray emission extends to very high energy (VHE > 100 GeV) gamma rays.Methods. We have observed MWC 656 with the MAGIC telescopes for ∼23 hours during two observation periods: between May and June 2012 and June 2013. During the last period, observations were performed contemporaneously with X-ray (XMM-Newton) and optical (STELLA) instruments.Results. We have not detected the MWC 656 binary system at TeV energies with the MAGIC Telescopes in either of the two campaigns carried out. Upper limits (ULs) to the integral flux above 300 GeV have been set, as well as differential ULs at a level of ∼ 5% of the Crab Nebula flux. The results obtained from the MAGIC observations do not support persistent emission of very high energy gamma rays from this system at a level of 2.4% the Crab flux. PB EDP SN 0004-6361 YR 2015 FD 2015-04 LK https://hdl.handle.net/20.500.14352/24006 UL https://hdl.handle.net/20.500.14352/24006 LA eng NO © ESO 2015. We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, the Swiss National Fund SNF, and the ERDF funds under the Spanish MINECO is gratefully acknowledged. This work was also supported by the CPAN CSD2007-00042 and MultiDark CSD2009-00064 projects of the Spanish Consolider-Ingenio 2010 programme, by grant 127740 of the Academy of Finland, by the Croatian Science Foundation (HrZZ) Project 09/176, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzWgrant 745/N-HESS-MAGIC/2010/0. J.C. acknowledges support by the Spanish Ministerio de Economía y Competividad (MINECO) under grant AYA2010-18080. The authors thank the anonymous referee for a thorough review and a very constructive list of remarks that helped improving the quality and clarity of this manuscript. NO German BMBF NO German MPG NO Italian INFN NO Spanish MINECO NO Academy of Finland, by the Croatian Science Foundation (HrZZ) NO DFG Collaborative Research Centers NO Polish MNiSzWgrant DS Docta Complutense RD 10 abr 2025