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GCN Circular 35113

GRB 231118A: Las Cumbres optical detection
2023-11-19T00:04:57Z (13 days ago)
Manisha Shrestha at University of Arizona <>
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M. Shrestha (Univ. of Arizona),  D. Sand (Univ. of Arizona), K. D. Alexander (Univ. of Arizona), J. Andrews (Gemini), J. Pearson (Univ. of Arizona), N. Smith (Univ. of Arizona), K. Bostroem (Univ. of Arizona) D. A. Howell (LCO/UCSB), C. McCully (LCO/UCSB), M. Newsome (LCO/UCSB), E Padilla Gonzalez (LCO/UCSB), C. Pellegrino (LCO/UCSB), G. Terreran (LCO/UCSB), J. Farah (LCO/UCSB) report on behalf of a wider Global Supernova Project collaboration:
We observed the field of GRB 231118A (Fermi GBM team GCN 34937, Swift GCN 34938) with the 1-m telescope, on 2023-11-18T22:30:11.370 UT (60266.937 MJD, ~5.3 hours after the trigger) using the Sinistro instrument in g, r, i bands. We detect the GRB with the following magnitude:
g = 19.81 +-0.09
r =  19.45 +-0.14
i =  19.44 +-0.19

Magnitudes were calculated with respect to ATLAS-REFCAT2 (Tonry et al. 2018, ApJ 867 105) catalog and are not corrected for galactic extinction. These values are consistent with other detections (Dutton et al., GCN 35103, Dutton et al., GCN 35108, Lipunov et al., GCN 35109, Strausbaugh et al., GCN 35110)

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