{
  "bibcode": "2020GCN.28880....1P",
  "body": "Gregory S.H. Paek (SNU), Myungshin Im (SNU), Joonho Kim (SNU), Gu Lim\n(SNU), Mankeun Jeong (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI),\nHyun-Il Sung (KASI),  Taewoo Kim (DOAO), and Wonseok Kang (DOAO) and GECKO\nteam\n\n We observed the ZTF20acozryr/AT2020yxz (Coughlin et al., GCN 28841) in\nBVRI with various optical telescopes of the GW EM-Counterpart Korean\nObservatory (GECKO). The facilities used for the observations are the 1.6-m\nclass telescopes of Korea Microlensing Telescope Network (KMTNet) located\nin Siding Spring Observatory (SSO) and South African Astronomical\nObservatory (SAAO), the 1-m telescope in Deokheung Optical Astronomy\nObservatory (DOAO), the 1-m telescope the Mt. Lemmon Optical Astronomy\nObservatory (LOAO), and the 0.36-m KIAS Chamnun Telescope (KCT) and RASA36\ntelescope in Chile. We calibrated flux with PS1 and APASS catalog, and the\nmagnitudes are in AB system. The magnitudes are not corrected for galactic\nextinction. Preliminary R-band magnitudes are given for the most recent a\nfew epoch observations.\n\nObs.&Tel.           DATE-OBS(UT)    Filter   Mag    Error  t-t0(days since\nburst)\n----------- ----------------------- ------ ------- -------\n----------------------\nDOAO        2020-11-08T19:51:31     R      21.6    0.1     5.07\nKCT         2020-11-10T04:27:38     R      21.8    0.3     6.43\nKMTNet-SAAO 2020-11-10T21:37:55     R      21.8    0.1     7.1\n\nt0 = 2020-11-03T18:06:45.36 (Ursi et al., GCN 28831)\n\nAbout a week after GRB occurs, the brightness seems to remain nearly\nconstant, suggesting a possible onset of a supernova component accompanied\nwith GRB.\n\nWe thank all the operators at GECKO facilities for performing the\nobservation.\n\nGravitational-wave EM Counterpart Korean Observatory (GECKO) is a network\nof 10+ 0.5m to 1m class telescopes over the world.",
  "circularId": 28880,
  "createdOn": 1605095689000,
  "email": "shpaek@astro.snu.ac.kr",
  "subject": "ZTF20acozryr/AT2020yxz (GRB 201103B): Flattening of the optical light curve",
  "submitter": "Gregory SungHak Paek at SNU  <shpaek@astro.snu.ac.kr>",
  "eventId": "ZTF20acozryr"
}