{
  "subject": "IceCube-240105A: ZTF optical observation of blazar PKS 0446+11",
  "circularId": 35548,
  "eventId": "IceCube-240105A",
  "submittedHow": "web",
  "body": "Jannis Necker (DESY), Simeon Reusch (DESY), Robert Stein (Caltech), Sven Weimann (Ruhr University Bochum) and Anna Franckowiak (DESY/Ruhr University Bochum) report:\n\nWe observed the blazar PKS 0446+11 with the Palomar 48-inch telescope as part of our ZTF neutrino follow up campaign (Necker et. al, GCN 35510) of IceCube-240105A (Sommani et. al, GCN 35498). \n\nThe blazar is detected over 2000 days with clear signs of variability. It recently reached its peak brightness in g-band in November after a around one month long rise in both g- and r-band, which coincides with activities in gamma-rays (ATEL #16398) and radio (ATEL #16399). At 2024-01-06T06:16:01.001280, we measured the all-time peak r-band brightness (17.1mag) only around 17 hours after the detection of IceCube-240105A, coinciding with the recent activitiy in X-rays (ATEL #16397). The blazar has since faded in both bands to 19.5mag in g-band and 18.3mag in r-band.\n\nThe blazar was not selected as a candidate counterpart by our automatic follow-up pipeline because it got rejected as a star based on a metric derived from Pan-STARRS data (Tachibana & Miller, 2018, PASP 130 128001).\n\nZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA; WIS, Israel; OKC, Sweden; JSI/UMd, USA; DESY, Germany; TANGO, Taiwan; UW Milwaukee, USA; LANL, USA; TCD, Ireland; IN2P3, France.\n\nGROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949.\nAlert distribution service provided by DIRAC@UW (Patterson et al. 2019).\nAlert database searches are done by AMPEL (Nordin et al. 2019).\nAlert filtering is performed with the nuztf (Stein et al. 2021, https://github.com/desy-multimessenger/nuztf ).",
  "submitter": "Jannis Necker at DESY <jannis.necker@desy.de>",
  "bibcode": "2024GCN.35548....1N",
  "createdOn": 1705435770984
}