Observations of the First Electromagnetic Counterpart to a Gravitational-wave Source by the TOROS Collaboration

DÍAZ, M.C.; MACRI, L.M.; LAMBAS, D. GARCIA; OLIVEIRA, C. MENDES DE; CASTELLÓN, J. L. NILO; RIBEIRO, T.; SÁNCHEZ, B.; SCHOENELL, W.; ABRAMO, L.R.; AKRAS, S.; ALCANIZ, J.S.; ARTOLA, R.; BEROIZ, M.; BONOLI, S.; CABRAL, J.; CAMUCCIO, R.; CASTILLO, M.; CHAVUSHYAN, V.; COELHO, P.; COLAZO, C.; COSTA-DUARTE, M.V.; LARENAS, H. CUEVAS; DEPOY, D.L.; ROMERO, M. DOMÍNGUEZ; DULTZIN, D.; FERNÁNDEZ, D.; GARCÍA, J.; GIRARDINI, C.; GONÇALVES, D.R.; GONÇALVES, T.S.; GUROVICH, S.; JIMÉNEZ-TEJA, Y.; KANAAN, A.; LARES, M.; LOPES DE OLIVEIRA, R.; LÓPEZ-CRUZ, O.; MARSHALL, J.L.; MELIA, R.; MOLINO, A.; PADILLA, N.; PEÑUELA, T.; PLACCO, V.M.; QUIÑONES, C.; RIVERA, A. RAMÍREZ; RENZI, V.; RIGUCCINI, L.; RÍOS-LÓPEZ, E.; RODRIGUEZ, H.; SAMPEDRO, L.; SCHNEITER, M.; SODRÉ, L.; STARCK, M.; TORRES-FLORES, S.; TORNATORE, M.; ZADROZNY, A.

Astrophysical Journal Letters

Institute of Physics Publishing

Lugar: Washington; Año: 2017 vol. 848

2041-8205

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 (Δg = 0.17 ± 0.03 mag, Δr = 0.14 ± 0.02 mag, Δi = 0.10 ± 0.03 mag) over the course of only 80 minutes of observations obtained ∼35 hr after the trigger with the T80-South telescope. A second epoch of observations, obtained ∼59 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.