GCN Circular 33293
Subject
GRB 230204B: LCOGT Optical Upper Limits
Date
2023-02-06T21:29:51Z (a year ago)
From
Robert Strausbaugh at University of Minnesota <rstrausb@umn.edu>
R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on
behalf of a larger collaboration:
We observed the GRB 230204B (Serino et al., GCN 33265) field with the LCOGT
1-meter Sinistro instrument at the Siding Spring Observatory, Australia
site, on February 6, from 15:27 to 16:24 UT (corresponding to 38.33 to 39.3
hours from the GRB trigger time) with the SDSS g, r, and i filters.
We performed a series of 3x300s exposures in each band. We do not detect a
source in any band at the GIT optical counterpart location (Swain et al.,
GCN 33269), evidence for additional fading compared to early optical
detections (Swain et al., GCN 33269; Smartt et al., GCN 33278; Saccardi et
al., GCN 33281; Ror et al., GCN 33284).
The following upper limits are calculated using the PanSTARRS catalog as
reference:
g > 22.0
r > 21.9
i > 21.1
These magnitudes are not corrected for galactic extinction.