TITLE: GCN CIRCULAR NUMBER: 25657 SUBJECT: GRB 190829A: Liverpool Telescope observations of a slow supernova rise DATE: 19/09/04 16:36:59 GMT FROM: Daniel Perley at Liverpool JMU D. A. Perley and A. M. Cockeram (LJMU) report: We obtained another epoch of r/i/z imaging of the optical counterpart of GRB 190829A (Dichiara et al., GCN 25552; Lesage et al., GCN 25575; Xu et al., GCN 25555) with IO:O on the Liverpool Telescope Telescope on 2019-09-04 between 04:43 and 05:32 UT. Image subtraction was performed using PS1 imaging as a template. We report the following photometry: t-t0 filt mag unc ------ ---- ----- ---- 5.3707 i 21.32 +/- 0.09 5.3941 z 20.61 +/- 0.10 This is consistent with a continued, slight rise compared to our previous two LT epochs (e.g., i = 21.45 at t = 4.29 days; GCN 25623) and with our earlier interpretation of the light curve flattening as the appearance of an associated supernova. Spectroscopic confirmation is still necessary to solidify this interpretation. We note that our z-band measurement is 1 magnitude fainter than that reported by Bolmer et al. (GCN 25651) at a similar epoch, and we do not confirm the sharp, short-timescale rise that they report. It is possible that the difference arises due to lack of host galaxy subtraction in the GROND photometry. DisclaimerNone