{
  "bibcode": "2017GCN.21566....1I",
  "body": "M. Im, C. Choi, J. Kim, H. M. Lee (SNU), S.-L. Kim (KASI) on behalf of the\nKU collaboration\n\n\n\nWe analyzed the medium-band data we took for SSS17a at the Siding Spring\nObservatory at 2017-08-18.4 (UT) in Im et al. (LVC GCN 21563). The\npreliminary magnitude at the medium-band filter m475 centered at 475nm\n(Choi & Im JKAS, 50, 71) is m475 = 17.5 +- 0.2 AB mag, somewhat brighter\nthan g ~ 17.9 mag of Wolf et al. (LVC GCN 21560) taken at the same site at\na similar time. Considering that m475 is similar to the g-band filter, this\nprefers a moderate dimming in comparison to g=17.2 +- 0.1 mag at the time\nof 2017-08-18.1 (UT) from Simon et al. (LVC GCN 21551) to a brightening as\nsuggested by Arcavi et al. (LVC GCN 21565). However, currently, the large\nuncertainties in the magnitude estimates (mostly due to host galaxy\nsubtraction problem) makes us difficult to rule out no brightening or even\na slight brightening of the EM counterpart candidate.",
  "circularId": 21566,
  "createdOn": 1503076543000,
  "email": "myungshin.im@gmail.com",
  "subject": "LIGO/Virgo G298048: Moderate dimming or no brightening of the optical counterpart candidate?",
  "submitter": "Myungshin Im at Seoul National U  <myungshin.im@gmail.com>",
  "eventId": "LIGO/Virgo G298048"
}