We present the results of prompt optical follow-up of the electromagnetic counterpart of the gravitational-wave event GW170817 by the Transient Optical Robotic Observatory of the South Collaboration. We detected highly significant dimming in the light curves of the counterpart (Î”g = 0.17 Â± 0.03 mag, Î”r = 0.14 Â± 0.02 mag, Î”i = 0.10 Â± 0.03 mag) over the course of only 80 minutes of observations obtained âˆ¼35 hr after the trigger with the T80-South telescope. A second epoch of observations, obtained âˆ¼59 hr after the event with the EABA 1.5 m telescope, confirms the fast fading nature of the transient. The observed colors of the counterpart suggest that this event was a \"blue kilonova\" relatively free of lanthanides.
M. C. Díaz, et. al., (2017) Observations of the First Electromagnetic Counterpart to a Gravitational-wave Source by the TOROS Collaboration.Astrophysical Journal Letters848:2. DOI: http://doi.org/10.3847/2041-8213/aa9060
Astrophysical Journal Letters