{
  "bibcode": "2020GCN.28756....1I",
  "body": "Myungshin Im, Gregory S. Paek, Gu Lim, Sungyong Hwang (CEOU/SNU) and H.-I.\nSung (KASI), on behalf of a larger collaboration\n\nUsing the LOAO 1m telescope at Mt. Lemmon, Arizona, USA, we observed the\nfield centered on WISEA J172314.13+142101.5, an IR source suggested as a\npossible counterpart of the gamma ray source Fermi J1725.5+1312 (Buson et\nal., GCN 28751). Note that  Fermi J1725.5+1312 is a new gamma ray source\nthat appeared recently within the 90% localization of the neutrino event,\nIC201021A (IceCube collaboration, GCN 28715). The observation started at\n2020-10-23 01:51:54 (UT). The images were taken in R-band with on-source\nintegration time of 27 min.\n\nWe find an optical counterpart of WISEA J172314.13+142101.5 near the\ndetection limit of the stacked LOAO image with a tentative magnitude of\nR=21.0 +- 0.3 AB mag. The PS1 DR2 archive (Chambers, K. C. et al.) shows\nthat this source has a mean magnitude of r=21.22 +- 0.04 AB mag (PSF\nmagnitude). Examination of the PS1 data also shows the variability of this\nobject at the level of a few tenths of magnitude in the past. Our result\nindicates that the object has not brightened significantly (<0.2 mag)\ncompared to the historic mean. A deeper observation is desirable to better\nconstrain the current optical variability state of this source.\n\nWe thank the staff of LOAO, Jaehyuk Yoon, for performing the observation.",
  "circularId": 28756,
  "createdOn": 1603440506000,
  "email": "mim@astro.snu.ac.kr",
  "subject": "IceCube-201021A: Optical counterpart of WISEA J172314.13+142101.5",
  "submitter": "Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>",
  "eventId": "IceCube-201021A"
}