TITLE: GCN CIRCULAR NUMBER: 16899 SUBJECT: GRB 141004A: GROND observations DATE: 14/10/06 19:23:19 GMT FROM: Sebastian Schmidl at TLS Tautenburg S. Schmidl (TLS Tautenburg), J. F. Graham, and J. Greiner (both MPE Garching) report on behalf of the GROND team: We observed the field of GRB 141004A (Swift trigger 614390; V. D'Elia et al., GCN #16878) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). We detect the afterglow at the UVOT position reported by V. D'Elia et al. (GCN #16878). From coadded observations, starting on October 06 and spanning from 05:31 to 09:09 UT, we report the following preliminary AB magnitudes of: g' = 24.6 +/- 0.3, r' = 24.0 +/- 0.2, i' = 23.5 +/- 0.2, and z' = 23.4 +/- 0.2. Given magnitudes are calibrated against GROND zeropoints and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.32 mag in the direction of the burst (Schlegel et al. 1998).