{
  "submittedHow": "web",
  "eventType": [
    "GRB",
    "Optical Transient"
  ],
  "subject": "GRB 260915A: 10.4m GTC deep optical limits",
  "format": "text/plain",
  "circularId": 45578,
  "eventId": "GRB 260915A",
  "createdOn": 1789460808272,
  "submitter": "I. Perez-Garcia at Instituto de Astrofísica de Andalucía <ipg@iaa.es>",
  "body": "I. Perez-Garcia, A. Sota, M.D. Caballero-Garcia, M. Gritsevich, S.-Y. Wu, S. Guziy (IAA-CSIC), Y.-D. Hu (GXU), D. Slumstrup, D. Perez-Valladares (IAC, GRANTECAN) and A.J. Castro-Tirado (IAA-CSIC), on behalf of a larger collaboration\n\nFollowing the detection of GRB 260915A by SVOM/ECLAIRs (Liang et al. GCN 45570), we triggered the 10.4m GTC telescope equipped with OSIRIS in La Palma (Spain). Images in the Sloan i, z and r bands were gathered on Sep. 15 starting at 05:20 UT (i.e. ~4.1 hours after the trigger), at high airmass (~1.55) and under variable transparency, covering the SVOM/MXT error circle (Liang et al. GCN 45570). No optical transient is detected within the error circle down to 3-sigma limits of r = 24.58 mag, i = 22.82 and z = 23.71 (100 s, 100 s and 240 s  of exposure, respectively).\n\nMagnitudes are in the AB system, calibrated against ATLAS-REFCAT2, and not corrected for Galactic extinction.\n\nThese non-detections are consistent with the reports from LCO (Yin et al. GCN 45573), SVOM/VT (Wu et al. GCN 45575) and NOT (Zhu et al. GCN 45577).\n\nWe thank the staff at GTC for their excellent support."
}