{
  "bibcode": "2021GCN.30837....1N",
  "body": "A. Nicuesa Guelbenzu, S. Klose, S. Melnikov, B. Stecklum, C. Hoegner (all\nTLS Tautenburg) report:\n\nWe observed the field of GRB 210912A (Troja et al., GCN 30820) with the\nTautenburg 1.34m Schmidt telescope equipped with the TAUKAM 6kx6k CCD\ncamera and the Sloan r-band filter.\n\nObservations were performed on September 12, at a midtime of 19.33 UT,\n22.17 UT, and 02:36 UT (Sep 13). The optical transient (Hu et al., GCN\n30823; Pankov et al., GCN 30825; Kuin & Troja, GCN 30832; Kann et al. GCN\n30833) is detected with the following preliminary AB magnitudes:\n\nr_1 = 21.95 +- 0.19,\nr_2 = 22.17 +- 0.19,\nr_3 = 22.53 +- 0.19.\n\nMagnitudes are calibrated against the Pan-STARRS catalogue.\n\nA comparison with the previous observations suggests that around 0.6 days\nthe decay index of the light curve has increased from a rather modest\nvalue of alpha = 0.4 to alpha about 1. Further observations are required\nin order to provide a more precise decay index.",
  "circularId": 30837,
  "createdOn": 1631550304000,
  "email": "ana@tls-tautenburg.de",
  "subject": "GRB 210912A: Tautenburg observations",
  "submitter": "Ana Nicuesa at TLS Tautenburg  <ana@tls-tautenburg.de>",
  "eventId": "GRB 210912A"
}