{
  "bibcode": "2022GCN.31619....1H",
  "body": "Anna Y. Q. Ho (UCB), Daniel Perley (LJMU), Igor Andreoni (JSI), Mansi\nKasliwal (Caltech), Dmitry Svinkin (Ioffe Institute), Aaron Tohuvavohu (U.\nToronto), Harsh Kumar (IITB) on behalf of the Zwicky Transient Facility\n(ZTF) collaboration:\n\nWe report the discovery of ZTF22aabjpxh (AT2022cva), a rapidly fading red\ntransient located at\n\n16:03:39.35  +31:14:04.72 (J2000)\n240.9139656,  31.2346451 (J2000)\n\nfirst detected as part of the ZTF partnership survey.\n\nThe source was discovered on JD 2459630.0001 at r=16.59 �� 0.01 mag, which\nwas 0.98 days after the last non-detection (r>19.34). The transient\nposition is 2'' from a galaxy in SDSS with a photometric redshift of 0.25 ��\n0.05. Due to the rapid rise of almost 3 magnitudes in one day, and the\npossible high luminosity, we triggered follow-up photometry with the\nSpectral Energy Distribution Machine (SEDM) on the 60-inch telescope at\nPalomar Observatory (P60). SEDM photometry obtained the night after\ndiscovery established a rapid fade rate of 2.25 magnitudes in 0.88 days as\nwell as red colors (g-r=0.41 �� 0.08, corrected for Galactic extinction).\nThe transient was also detected as part of the ZTF public survey that\nnight, and the rapid fade triggered the ZTFReST pipeline (Andreoni &\nCoughlin et al. 2021).\n\nKonus-Wind detected a long-duration GRB at UT 2022-02-19 09:27:25.350 that\nis consistent with the position of AT2022cva. The GRB burst time is 2.5\nhours before the first ZTF detection. The GRB was also weakly detected by\nBAT. The ZTF optical position was outside the coded BAT FoV at the time of\nthe burst, and the observed counts are consistent with a relatively soft\nburst coming from outside the BAT field of view. The Konus-BAT IPN annulus\nis consistent with the position of the ZTF transient, and the association\nis highly likely.\n\nWe conclude that AT2022cva is the likely afterglow to the Konus-Wind GRB.\nGiven the possible low redshift (z~0.3) continued photometric and\nspectroscopic observations are encouraged.\n\n\nBased on observations obtained with the Samuel Oschin Telescope 48-inch and\nthe 60-inch Telescope at the Palomar Observatory as part of the Zwicky\nTransient Facility project. ZTF is supported by the National Science\nFoundation under Grant No. AST-2034437 and a collaboration including\nCaltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center\nat Stockholm University, the University of Maryland, Deutsches\nElektronen-Synchrotron and Humboldt University, the TANGO Consortium of\nTaiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin,\nLawrence Livermore National Laboratories, IN2P3, University of Warwick,\nRuhr University Bochum and Northwestern University. Operations are\nconducted by COO, IPAC, and UW.\n\n-- \nAnna Ho",
  "circularId": 31619,
  "createdOn": 1645416798000,
  "email": "annayqho@berkeley.edu",
  "subject": "ZTF22aabjpxh/AT2022cva: ZTF Discovery of a Rapidly Fading Transient with a Likely Long-GRB Counterpart",
  "submitter": "Anna Ho at UC Berkeley  <annayqho@berkeley.edu>",
  "eventId": "ZTF22aabjpxh"
}