TY - JOUR AU - Caballero, J. A. AU - López Santiago, Javier AU - Castro Rubio, Elisa de AU - Cornide Castro-Piñeiro, Manuel PY - 2009 DO - 10.1088/0004-6256/137/6/5012 SN - 0004-6256 UR - https://hdl.handle.net/20.500.14352/43018 T2 - Astronomical journal AB - We used the Aladin Virtual Observatory tool and High Resolution Imager ROSAT archival data to search for X-ray variability in scale of days in 23 young stars in the σ Orionis cluster and a background galaxy. Five stars displayed unambiguous flares and... LA - eng M2 - 5012 PB - IOP Publishing ltd KW - Main-sequence stars KW - T-Tauri stars KW - Serendipitous source catalog KW - XMM-Newton observations KW - All-sky survey KW - Brown dwarfs KW - Resolution spectroscopy KW - Energy-distributions KW - Molecular cloud KW - Space-telescope TI - X-ray variability of σ orionis young stars as observed with ROSAT TY - journal article VL - 137 ER -