TITLE: GCN CIRCULAR NUMBER: 43608 SUBJECT: GRB 251230A: MeerLICHT afterglow detection DATE: 26/02/03 07:50:51 GMT FROM: Simon de Wet at DTU Space <simdewet@gmail.com> S. de Wet (DTU Space) and P.J. Groot (Radboud/UCT/SAAO) report on behalf of the MeerLICHT consortium: The 0.6m wide-field MeerLICHT optical telescope located in Sutherland, South Africa, obtained a repeating series of 60s exposures in the q,u,g,r,i,z filters following the detection of GRB 251230A by Swift (Lanava et al., GCN 43252). Our observations began 185 seconds after the Swift trigger and continued for approximately 26 minutes following the filter sequence quqgqrqiqz. A further four exposures were taken after a gap of approximately 30 minutes. We detect the bright optical afterglow in all of our images, and report the following first detections in each filter: q = 12.99 +/- 0.01 at 01:25:21 UT u = 13.95 +/- 0.05 at 01:26:41 UT g = 14.24 +/- 0.02 at 01:29:24 UT r = 14.43 +/- 0.01 at 01:32:07 UT i = 14.67 +/- 0.01 at 01:34:51 UT z = 14.80 +/- 0.03 at 01:37:36 UT We measure a power-law decline rate of -1.54 in the q-band. A light curve is available at the following link: https://raw.githubusercontent.com/simdewet/GRB_lightcurves/main/GRB251230A.p... MeerLICHT is built and run by a consortium consisting of Radboud University, University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam. View this GCN Circular online at https://gcn.nasa.gov/circulars/43608. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...