{
  "createdOn": 1687170174255,
  "body": "R. Strausbaugh (UMN), O. Pyshna (AO TSNU of Kyiv), T. du Laz (CIT),\nS. Pormente (OCA), A. Takey, A. Shokry, A. Fouad, M. Molham, A. Tawfeek\n(NRIAG), S. Antier (OCA), M. Coughlin (UMN), P. Hello (IJCLAB),\nS. Karpov, M. Prouza, M. Mašek, M. Blazek (FZU), A. Klotz (IRAP),\nT. Pradier (Univ. Strasbourg), I. Tosta e Melo (UNICT), D. Turpin (CEA),\nO.Burkhonov (UBAI), S.Ehgamberdiev (UBAI, NUUz), Y.Rajabov (UBAI),\nT.Sadibekova (UBAI-CEA), Y.Tillayev (UBAI, NUUz), Xinglong ,\nF. Guo (THU), X. F. Wang (THU), Y. Zhu (NAOC), J. Zhang (NAOC),\nR. Inasaridze, R. Natsvlishvili, N. Kochiashvili, S. Beradze,\nV.Aivazyan (AbAO), report on behalf of the GRANDMA collaboration:\n\nThe GRANDMA telescope network responded to the GOTO and GIT triggers\nfrom LIGO/Virgo/KAGRA S230615az (Gompertz et al., GCN 33979, Kumar et al.,\nGCN 33974, TNS 2023kvr).\n\nThe first observations started 20 hours after the reported detection\ntime from the sources candidates.\n\nAs time reference (T0), we choose:\nfor GOTO23hn 2023-06-15T21:27:14.688 UT (60110.89392 MJD)\nfor GOTO23hu 2023-06-15T21:35:15.936 UT (60110.89949 MJD)\nfor GIT230615aa 2023-06-15T18:30:26.928 UT (60110.77114 MJD)\nfor GIT230615ab 2023-06-15T18:53:10.838 UT (60110.78693 MJD)\n\nIn the following table we report a subset of the preliminary photometry\nof our observations. Upper limits are reported as the faintest\nsource detected in frame; magnitudes and upper limits are reported\nin the AB system.\n\nGOTO23hn:\nT-T0 (day) |MJD   | Obser.   |Exposure| Filter | Mag +/- err  |Upp.Lim. (AB)\n________________________________________________________________________\n0.847|60111.74163|AbAO-T70|14x60s|R| - | > 20.6\n0.956|60111.84993|KAO|7x120s|sdssr| 18.9 +/- 0.05 |     -\n1.038|60111.93207|FRAM-CTA-N|28x120s|R| - |     > 18.7\n\n\nGOTO23hu:\nT-T0 (day) |MJD   | Obser.   |Exposure| Filter | Mag +/- err  |Upp.Lim. (AB)\n________________________________________________________________________\n0.862|60111.76180|AbAO-T70|15×60s|R| - | > 20.9\n0.984|60111.88393|FRAM-CTA-N|29x120s|R| - |     > 18.6\n\n\nGIT230615aa:\nT-T0 (day) |MJD   | Obser.   |Exposure| Filter | Mag +/- err  |Upp.Lim. (AB)\n________________________________________________________________________\n0.939|60111.71026|UBAI-NT60|10x180s|R| - |     > 20.3\n0.942|60111.72810|SNOVA|2x180s|C| - |     > 19.2\n1.099|60111.87106|KAO|7x120s|sdssr| - |     > 20.3\n\n\nGIT230615ab:\nT-T0 (day) |MJD   | Obser.   |Exposure| Filter | Mag +/- err  |Upp.Lim. (AB)\n________________________________________________________________________\n0.954|60111.72906|SNOVA|1x180s|C| - |     > 18.5\n0.997|60111.78488|AbAO-T70|12×60s|R| - | > 21\n1.037|60111.82444|KAO| 7x120s |sdssr| - |     > 21.3\n\nKAO data has been calibrated with respect to the PS1 catalog.\nFRAM-CTA-N data has been calibrated with respect to the APASS catalog.\nAbastumani-T70 data has been calibrated with respect to the PS1 catalog.\n\nThis single detection of GOTO23hn indicates that the source is either flat\nor increasing in brightness, but we note the difficulty of comparing\nthis narrow-band value to the original wide-band detection by GOTO.\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/).",
  "circularId": 34020,
  "submitter": "Aleksandra Pyshna at Astronomical Observatory of Taras Shevchenko National University of Kyiv, Kyiv, Ukraine <pyshnaya.sasha@gmail.com>",
  "subject": "LIGO/Virgo/KAGRA S230615az: GRANDMA observations of GOTO and GIT candidates",
  "eventId": "LIGO/Virgo/KAGRA S230615az",
  "bibcode": "2023GCN.34020....1S"
}