TITLE: GCN CIRCULAR NUMBER: 7502 SUBJECT: GRB 080319B: TORTORA light curve DATE: 08/03/21 19:54:17 GMT FROM: Sergey Karpov at SAO RAS S. Karpov, G. Beskin (SAO RAS, Russia), S. Bondar (RIPI, Russia), C. Bartolini, G. Greco, A. Guarnieri, A. Piccioni (Astronomy Department of Bologna University, Italy), D. Nanni, F. Terra (Second University of Roma "Tor Vergata", Italy), E. Molinari, G. Chincarini, F.M. Zerbi, S. Covino, V. Testa (Osservatorio Astronomico di Brera, Italy), G. Tosti (Universita di Perugia, Italy), F. Vitali, L.A. Antonelli (Osservatorio Astronomico di Roma, Italy), P. Conconi, G. Cutispoto (Osservatorio Astronomico di Catania, Italy), G. Malaspina (Osservatorio Astronomico di Brera, Italy), L. Nicastro (Istituto di Astrofisica Spaziale e Fisica Cosmica, Palermo, Italy), E. Palazzi (Istituto di Astrofisica Spaziale e Fisica Cosmica, Bologna, Italy), E. Meurs (Dunsink Observatory, Ireland), P. Goldoni (Observatori Astronomic - Universitat de Valencia Edificio de Institutos de Investigacion, Spain) report on behalf of TORTOREM team: Following GCN 7452 we publish a preliminary light curve of GRB 080319b with reduced temporal resolution (10 frames time binning, 1.3 seconds effective exposure, no gaps between frames). The photometry is performed in instrumental system and calibrated towards the V magnitudes of nearby Tycho2 stars. The light curve is available online at http://vo.astronet.ru/~karpov/grb080319b_lc_10.gif The light curve shows fast (~5 seconds) uprise towards the peak V=5.5 at T+23, complex multi-peak structure till T+50 and featureless decay then. In total, the transient has been visible for ~65 seconds; 6 seconds in the T+30 - T+36 interval are currently excluded from the analysis due to repointing of REM telescope at that time. The light curve is consistent with the one published by Pi of the Sky (Cwiok et al, GCN 7445). The video sequence of the data is available at http://vo.astronet.ru/~karpov/grb080319b.avi and with reduced temporal resolution at http://vo.astronet.ru/~karpov/grb080319b_lowres.avi The results of analysis of full-resolution (0.13s exposure) data will be published later.