TITLE: GCN CIRCULAR NUMBER: 5734 SUBJECT: GRB 061019: SMARTS afterglow confirmation DATE: 06/10/19 16:25:49 GMT FROM: Bethany Cobb at Yale U B. E. Cobb (Yale), part of the larger SMARTS consortium, reports: Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 061019 (GCN 5728, Guidorzi et al.) with a mid-exposure time of 2006-10-19 07:29 UT, which is ~3.2 hours post-burst. Total summed exposure times amounted to 15 minutes in I and V and 12 minutes in J and K. Within the error region of the X-ray afterglow detection (GCN 5729, Guidorzi et al.), we detect the source reported by Covino et al. (GCN 5730), in the I, J and K bands. The source is not detected in V, to a limiting magnitude of ~22. The preliminary magnitudes of this source (calibrated against several 2MASS stars in IR and USNO-B1.0 stars in the optical) are: time post- burst (hrs) I J K ------------------------------------------------------------ 3.2 20.2 +/- 0.3 17.6 +/- 0.1 15.4 +/- 0.1 (not corrected for the expected high Galactic extinction) This indicates that the source has faded by ~1 magnitude since the Covino et al. K-band observations, taken ~1.1 hours post-burst. This source is therefore confirmed to be the afterglow of GRB 061019, wth a decay rate of alpha ~ -0.8. [GCN OPS NOTE(19oct06): Per author's request, the J-band value was corrected from 17.9 to 17.6.]