TITLE: GCN CIRCULAR NUMBER: 19981 SUBJECT: GRB 161004A: Bassano Bresciano Observatory upper limit DATE: 16/10/04 19:14:38 GMT FROM: Ulisse Quadri at Bassano Bresciano Obs U.Quadri, L.Strabla and R.Girelli report: We imaged the field of GRB 161004A detected by SWIFT(trigger 715084) with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy. Member of: AAVSO - American Association of Variable Star Observers. ISSP - Italian Supernovae Search Project. UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili. The observations started 4.90 hour after the GRB trigger, at the end of twilight, with our Newton telescope D=250 mm F/D=4.8. Weather conditions were good. We co-added 3 series of 10 exposures of 60 sec each. Start T0+ End T0+ Vlim 4.9 hour 5.5 hour 18 We did not found any optical counterpart in the error box of the XRTcandidate. P.A. Evans (U Leicester), S. D. Barthelmy (GSFC), et al. Magnitudes were estimated with the UCAC4 cat. and are not corrected for galactic dust extinction. Reference: http://www.osservatoriobassano.org/GRB.asp The message may be cited.