{
  "bibcode": "2017GCN.21565....1A",
  "body": "I. Arcavi, D. A. Howell, C. McCully, G. Hosseinzadeh, S. Vasylyev (UCSB/Las\nCumbres Obs), M. Zalzman, D. Poznanski (TAU), L.P. Singer (NASA/GSFC), S.\nValenti (UC Davis), T. Piran (HUJI), D. Kasen, J. Barnes (UC Berkeley), W.\nFong (Northwestern) and D. Maoz (TAU) report the brightening of SSS17a /\nDLT17ck, the possible optical counterpart reported by Coulter et al. (LVC\nGCN 21529), Allam et al. (LVC GCN 21530), Yang et al. (LVC GCN 21531),\nMelandri et al. (LVC GCN 21532) and others.\n\nIn the course of Las Cumbres Observatory LIGO followup we observed NGC 4993\nfrom our 1-meter telescopes at the Cerro Tololo Inter-American Observatory\nin Chile at 2017-08-18 00:15 UT (Arcavi et al.; LCV GCN 21538) and at the\nSiding Spring Observatory in Australia at 2017-08-18 09:10 UT. Both images\nwere taken in the broad w (=g+r+i) filter.\n\nPreliminary aperture photometry, comparing to 7 nearby stars, indicates a\nrelative increase in brightness of the candidate by 0.11 magnitudes (with\nan uncertainty of 0.03 magnitudes) in the ~9 hours between the first and\nsecond epochs.\n\nFurther observations and analysis are ongoing.",
  "circularId": 21565,
  "createdOn": 1503071921000,
  "email": "iarcavi@lcogt.net",
  "subject": "LIGO/Virgo G298048: Brightening of Possible Counterpart",
  "submitter": "Iair Arcavi at LCOGT  <iarcavi@lcogt.net>",
  "eventId": "LIGO/Virgo G298048"
}