{
  "body": "O. Pyshna (AO TSNU of Kyiv), Z. Vidadi (ShAO), S. Beradze (AbAO), Y.Rajabov (UBAI), D. Aql (American Uni. SHJ), S. Antier (OCA), M. Coughlin (UMN), J. Peloton,  P. Hello (IJCLAB), S. Karpov, M. Prouza, M. Mašek, M. Blazek (FZU), A. Klotz (IRAP),T. Pradier (Univ. Strasbourg), I. Tosta e Melo (UNICT), D. Turpin (CEA), A. Takey, E. G. Elhosseiny, A. Abulwfa, M. A. El-Sadek, M. Molham (NRIAG), R. Inasaridze, R. Natsvlishvili, N. Kochiashvili, V. Aivazyan (AbAO), A. Baransky, Y. Romanyuk, O. Sokoliuk, A. Simon, V. Vasylenko (Lisnyky) report on behalf of the GRANDMA collaboration:\n\nGRANDMA observed the field of GRB 230812B (Lesage et al. GCN 34387; Scotton et al. GCN 34392; Page GCN 34394; Zheng\n& Filippenko GCN 34395; Lipunov et al. GCN 34396; Ackley et al. GCN 34398; Xiong et al. GCN 34401; Casentini et al. 34402; Frederiks et al. 34403; Mao et al. 34404; Odeh et al. 34405; Moskvitin & Spiridonova 34406; Leonini et al. 34408; de Ugarte Postigo et al. 34409; de Ugarte Postigo et al. 34410; Belkin et al. 34412; Ruocco et al. 34413; Frederiks et al. 34414; Ruocco et al. 34415; Shrestha et al. 34416; Quadri et al. 34417; Adami et al. 34418; Moretti et al. 34419; Kumar et al. 34420; Belkin et al. 34421) \nin particular ZTF23aaxeacr candidate afterglow (16:36:31.483 +47:51:32.26) (Salgundi et al. GCN 34397) \n\n\nThe first observation began about 22.56 hours from the trigger.\n\n\nAs time reference (T0), we choose: 2023-08-12T18:58:12 (60168.79041667 MJD) (Fermi GBM Team 34386)\n\nIn the following table we report a subset of the preliminary photometry\nof our observations. Magnitudes and upper limits are reported\nin the AB system.\n\nZTF23aaxeacr:\n\nT-T0 (day) |MJD   |Obser.   |Exposure| Filter | Mag +/- err  |Upp.Lim. (AB)\n--------------------------------------------------------------------------\n0.940|60169.73055556    |Abastumani-T70|46X60s |sdssr|20.35+/-0.12|21.3 (5sig)\n0.959|60169.75012731    |      KAO                   |10X180s|sdssg|20.53+/-0.05|21.7 (5sig)\n0.988|60169.77848380    |      KAO                   |10X180s|sdssr|20.23+/-0.05|21.5 (5sig)\n1.021|60169.81137731    |      KAO                   |20X150s|sdssi|20.17+/-0.03|22.3 (5sig)\n1.115|60169.90562500    |  FRAM-CTA-N      |50X60s |  R  |      -     |>19.1 (Vega)\n\n\nKAO data has been calibrated with respect to the PS1 catalog.\nAbastumani-T70 data has been calibrated with respect to the PS1 catalog, with the Johnson cousin conversion into sloan r.\nFRAM-CTA-N data has been calibrated with respect to the APASS catalog.\n\nGRANDMA is a worldwide coordinated telescope network\n(grandma.ijclab.in2p3.fr)  devoted to the observation of transients\nin the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS\n497, 5518). Kilonova-Catcher (KNC) is the citizen science program of\nGRANDMA (http://kilonovacatcher.in2p3.fr/).\n",
  "submitter": "Aleksandra Pyshna at Astronomical Observatory of Taras Shevchenko National University of Kyiv, Kyiv, Ukraine <pyshnaya.sasha@gmail.com>",
  "subject": "GRB 230812B: GRANDMA further observations of ZTF23aaxeacr candidate afterglow",
  "bibcode": "2023GCN.34425....1P",
  "eventId": "GRB 230812B",
  "submittedHow": "web",
  "circularId": 34425,
  "createdOn": 1692048518639
}