GCN Circular 32304
Subject
GRB 220627A, GROND observations
Event
Date
2022-06-30T15:07:56Z (4 years ago)
From
Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>
A. Nicuesa Guelbenzu, S. Klose (both TLS Tautenburg), and A. Rau (MPE
Garching) report:
We observed the field of GRB 220627A (Fermi GBM team, GCN 32278) with
GROND mounted at the 2.2m MPG telescope at La Silla Observatory (Chile).
Observations started at 01:30 UT on June 30, 2022, about 2.2 days after
the GRB trigger and were on target for 20 minutes. They were performed at
an average seeing of 0.8 arcsec and at an airmass of 1.1.
The reported optical transient (de Wet et al., GCN 32289; Izzo et al., GCN
32291) is detected in the optical but not in the NIR bands with the
following (preliminary) magnitudes and upper limits (AB mags; 3 sigma):
g' = 23.31 +/- 0.11,
r' = 22.70 +/- 0.06,
i' = 22.50 +/- 0.12,
z' = 22.23 +/- 0.21,
J > 21.4,
H > 20.6,
K > 19.7.
The given limits are derived based on calibrating the optical images
against the SM catalog and the JHK data against 2MASS stars.
We thank Regis Lachaume and Paul Eigenthaler for excellent support and for
performing the observations.