{
  "bibcode": "2023GCN.33229....1A",
  "body": "Igor Andreoni (JSI), Harsh Kumar (IITB), Michael Coughlin (UMN), Gaurav\nWaratkar (IITB), Eric Burns (LSU), Daniel Perley (LJMU)\n\nWe report the discovery of the very fast optical transient\nZTF23aabmzlp/AT2023azs with the Zwicky Transient Facility (ZTF, Bellm et\nal. 2019, Graham et al. 2019) at coordinates:\n\nRA = 11:30:16.49 (172.5687149d)\nDec = +65:51:10.01 (65.8527808d)\n\nZTF23aabmzlp was first detected on 2023-01-28 06:14 UT at r = 17.42 �� 0.04\nmag. ZTF23aabmzlp faded by 2.3 magnitudes in 6.2 hours in the r-band. The\nlast ZTF upper limit before the first detection was measured on 2023-01-28\n05:55 UT in g-band, which is about 19 minutes before the first detection.\nThere is no pre-detection at the transient location in 1,736 images of the\nfield previously acquired by the ZTF survey. ZTF photometry is reported in\nthe following table:\n\n----------------------------------\n     MJD       |     mag AB\n----------------------------------\n59972.24688660 | g > 19.7\n59972.25979170 | r = 17.42 +- 0.04\n59972.36381940 | g = 19.20 +- 0.11\n59972.43465280 | g = 19.60 +- 0.15\n59972.51854170 | r = 19.72 +- 0.20\n----------------------------------\n\nExtinction on the line of sight is negligible, with E(B-V)=0.01 mag. The\ntransient is located at high Galactic latitude b=49.2 deg. There is no\ncataloged source at the transient location in deep Legacy Survey DR9 and\nPan-STARRS (Chambers et al., 2016) archival images.\n\nNo gamma-ray triggers have been reported so far in the time window between\nthe last ZTF upper limit and the first detection. However, it is possible\nthat ZTF23aabmzlp/AT2023azs is a relativistic afterglow.\n\nFollow-up observations are strongly encouraged.\n\nZTF23aabmzlp was discovered by the ������ZTF Realtime Search and Triggering������\nproject (ZTFReST; Andreoni & Coughlin et al., 2021) within the ZTF\nCollaboration.\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, and IN2P3, France. Operations are\nconducted by COO, IPAC, and UW.",
  "circularId": 33229,
  "createdOn": 1674929455000,
  "email": "igor.andreoni@gmail.com",
  "subject": "ZTF23aabmzlp/AT2023azs: Zwicky Transient Facility discovery of a fast optical transient",
  "submitter": "Igor Andreoni at JSI  <igor.andreoni@gmail.com>",
  "eventId": "ZTF23aabmzlp"
}