Skip to main content
New Swift-BAT/GUANO and IceCube Notice Types Available! See news and announcements

GCN Circular 30168

GRB210610A: MeerLICHT multi-colour photometry
2021-06-10T18:56:04Z (2 years ago)
Paul Vreeswijk at Radboud U/Nijmegen <>
S. de Wet (UCT), P.M. Vreeswijk (Radboud), P.J. Groot
(Radboud/UCT/SAAO), A. Levan (Radboud) report on behalf of the
MeerLICHT consortium:

Following the detection of GRB210610A by Swift and its optical
counterpart (Page et al., GCN 30160), reported at a redshift of z=3.54
by Zhu et al. (GCN 30163), the 0.6m MeerLICHT telescope, located at
Sutherland, South Africa began observations of the field at
2021-06-10, 16:48:47 UT with a repeating sequence of optical filters:
q,u,q,g,q,r,q,i,q,z, at 60s integration time each. The q-band
wavelength limits are 440-720nm.

First detections are:
q_AB = 19.60 +/- 0.08 +/- 0.02 at 16:48:47 UT
r_AB = 19.09 +/- 0.10 +/- 0.01 at 16:56:12 UT
i_AB = 18.74 +/- 0.12 +/- 0.02 at 16:59:10 UT
z_AB = 18.37 +/- 0.19 +/- 0.02 at 17:02:09 UT, 
where the first uncertainty on the magnitude is the statistical
uncertainty and the second is the uncertainty on the photometric

In g-band the afterglow is detected only once, at 17:08:11 UT, at
g_AB = 20.18 +/- 0.18 +/- 0.03, close to the limiting magnitude of the

The source is not detected in the u-band, starting at 16:50:11 UT, at
a 5-sigma limiting magnitude of u_AB > 18.76.

Further fading of the source is observed during the ongoing sequence. 

MeerLICHT is built and run by a consortium consisting of Radboud
University, the University of Cape Town, the South African Astronomical
Observatory, the University of Oxford, the University of Manchester
and the University of Amsterdam.
Looking for U.S. government information and services? Visit