Extreme microvariability of blazars: fact and fiction

A. T. ARAUDO; CELLONE, S. A.; ROMERO, GUSTAVO E

Congreso; Reunion Anual de la Asociacion Argentina de Astronomia; 2004

Recently, it has been suggested that the amplitude variations in some blazars can be of more than one magnitude within a few tens of minutes. In order to verify this claim, we have performed a study of three objecs that are supposed to display such an extreme behavior: the HPQ 1510-089 and the BL Lacs 0048-097 and 0754+100. We have taken into account the errors that can arise from the incorrect selection of comparison and control stars and from the contamination by the host galaxy.Variability was found in all cases, but the kind of phenomena reported by other authors for the same blazars were never detected. We show that an incorrect methodology for data reduction can lead to spurious variations if the error sources aforementioned are not considered.