TITLE: GCN CIRCULAR NUMBER: 33630 SUBJECT: GRB 230414B: Bassano Bresciano Observatory optical observations DATE: 23/04/15 14:51:21 GMT FROM: Ulisse Quadri at Bassano Bresciano Obs U.Quadri, L.Strabla report: We imaged the field of GRB 230414B detected by SWIFT(trigger 1164180) with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy. Member of: AAVSO - American Association of Variable Star Observers. UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili. The observations started 236.82 min min after the GRB trigger, at the end of twilight, with our Newton telescope D=250 mm F/D=4.8. We co-added 6 series of 30 exposures of 60 sec each. Start T0+ End T0+ Vlim 236.82 min 323.07 min 20.5 We detected a (fading) afterglow in the error box of the XRTcandidate. A. D'Ai (INAF-IASFPA), E. Ambrosi (INAF-IASFPA), et al. at the following position (+/- 2 arcsec): RA (J2000.0) = 12h 04m 22.64s DEC(J2000.0) = +53° 09' 16.4" The results of our photometry are: ----------------------------------------- Date UT CR-mag Middle +/- 0.05 ----------------------------------------- 2023 04 14.85273 19.76 2023 04 14.86022 19.74 2023 04 14.86771 19.76 2023 04 14.87519 20.02 2023 04 14.88268 19.96 2023 04 14.89017 20.01 ----------------------------------------- Magnitudes were estimated with the UCAC4 cat. and are not corrected for galactic dust extinction. The images are available at: http://www.osservatoriobassano.org/GRB.asp The message may be cited.