Difference: GCNCIRCULAR21895 ( vs. 1)

M. Diaz, L. Macri, J.L. Nilo Castellon, B. Sanchez, C. Mendes, C. Colazo, M. Schneitter, C. Girardini, D. Garcia Lambas, M. Beroiz, A. Zadrozny, R. Camuccio, M. Castillo. J. Garcia for the TOROS collaboration

We have completed the PSF photometry of the observations of GW170817 carried out at the T80S telescope and the EABA telescope on 08/18/2017 and 08/19/2017 (GCN 21619, GCN, 21620). We calibrated our measurements using the Pan-STARRS1 catalog available at STScI, using their reported PSF magnitudes and uncertainties. The mid-point of our observations was 1.467d after the GW trigger - LIGO/Virgo G298048- (Julian Date of 2457984.495). At that time, we measured magnitudes of g=18.60, r=17.99, i=17.80 with uncertainties of +-0.02 mag. Additionally with our observations utilizing the EABA telescope we obtained r=18.78+-0.03 at 2.456d after the GW trigger -LIGO/Virgo G298048-.

-- ThomasKupfer - 20 Sep 2017