TITLE:   GCN CIRCULAR
NUMBER:  25623
SUBJECT: GRB 190829A: Flattening of optical light curve from continued Liverpool Telescope photometry
DATE:    19/09/03 05:28:44 GMT
FROM:    Daniel Perley at Liverpool JMU  <d.a.perley@ljmu.ac.uk>

D. A. Perley and A. M. Cockeram (LJMU) report:

We obtained further observations of the afterglow of GRB 190829A 
(Dichiara et al., GCN 25552; Lesage et al., GCN 25575; Xu et al., GCN 
25555) with the IO:O imager on the 2m robotic Liverpool Telescope. 
Observations were conducted on 2019-09-02 (03:33-04:03 UT) and 
2019-09-03 (02:46-03:36 UT).

In all three filters, the optical afterglow has slowed its decay from 
its previous power-law decline (GCN 25597), with little additional 
evolution in flux over the past 48 hours.  There is tentative evidence 
for rebrightening in the i-band.  We interpret this as the beginning of 
the rise of an associated supernova, but this still requires 
spectroscopic confirmation.

Additional i-band photometry (all subtracted versus PS1 reference 
imaging, with times in days referenced to the Swift trigger) is as follows:

  t-t0    filt   mag       unc
  ------  ----   -----     ----
  3.3193  i    = 21.69 +/- 0.12
  4.2889  i    = 21.45 +/- 0.12












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