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GCN Circular 34651

GRB 230906A: BlackGEM upper limits
2023-09-10T15:28:47Z (7 months ago)
Simon de Wet at University of Cape Town <>
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S. de Wet (UCT), D. Pieterse (Radboud), P.J. Groot (Radboud/UCT/SAAO) and P.M. Vreeswijk (Radboud) report on behalf of the BlackGEM consortium:

Following the IPN localisation of the short GRB 230906A (Fermi GBM team, GCN 34631) by the Interplanetary Network (Kozyrev et al., GCN 34637), the BlackGEM Unit Telescope 3 (BG3-Opal) located at ESO La Silla, Chile, obtained 2 x 300 s exposures in the q-band (440-720 nm) of the IPN triangulation region. The first observation started at 08:00:42 UT on 2023 September 7, 19.1 hours after the Fermi GBM trigger.

We detect no new transients within the IPN triangulation error region nor at the position of the Swift XRT source (Beardmore et al., GCN 34639) down to a 5-sigma limiting AB magnitude of q=21.53, consistent with the upper limits reported by Swift/UVOT (Oates and Moss, GCN 34643). The depth of our images was negatively affected by ~3 arcsecond seeing.  

BlackGEM is an array of wide-field telescopes designed, built and operated by a consortium consisting of Radboud University, the Netherlands Research School for Astronomy NOVA, KU Leuven, the University of Manchester, Tel Aviv University, the Weizmann Institute, the Hebrew University of Jerusalem, the University of Potsdam, Texas Tech University, the University of California at Davis, the Danish Technical University and the Armagh Observatory and Planetarium.
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