TITLE: GCN CIRCULAR NUMBER: 14504 SUBJECT: GRB 130418A: Bassano Bresciano Observatory lightcurve analisis DATE: 13/04/29 17:30:35 GMT FROM: Ulisse Quadri at Bassano Bresciano Obs U.Quadri, L.Strabla, R.Girelli and A.Quadri report: Photometric optical measurements of GRB 130418A detected by SWIFT trigger 553847 (de Pasquale et al. 2013; GCN Circ. 14377) have been done using the Schmidt telescope 0.32m F/3.1 and Starlight CCD camera HX-516 applied at direct focus. 120 sec. exposure time and 2x2 binning were used for all photos. All exposure were unfiltered. Flat field and dark have been captured and all images were corrected with them. Astrometrica software version 4.6.5.390 was used to perform differential photometry on the reduced images. began of period: 2013/04/18.80415 - 17 min after the burst. end of period: 2013/04/18.92338 - 188 min after the burst. The photometric results as follow: ------------------------------------ Date UTC Mag. 1 sigma. ------------------------------------ 2013 04 18.80485 15.68 0.08 2013 04 18.80846 16.12 0.13 2013 04 18.82000 16.44 0.10 2013 04 18.90014 17.64 0.08 2013 04 18.85910 17.21 0.13 2013 04 18.87354 17.39 0.12 2013 04 18.88799 17.53 0.09 2013 04 18.90968 17.74 0.09 ------------------------------------ Magnitudes were estimated with the USNO-B1 cat. and are not corrected for galactic dust extinction. Images and analisis are available at the following address: http://www.osservatoriobassano.org/archivio/grb/GRB130418A-Trig-553847-2013-04-18.htm This message may be cited.