GCN Circular 33550

F. Kugel (KNC), D. Turpin (CEA), S. Karpov (FZU), T. Hussenot-Desenonges 
(IJCLab), S. Antier (OCA/Artemis), P.A. Duverne (APC, U. Paris Cit�),
P. Hello (IJCLab), A. Klotz (OMP/IRAP) report on behalf of the 
GRANDMA/Kilonova-Catcher collaboration:

The Kilonova-Catcher telescope network responded to the alert of 
GRB 230328B (Swift detection: Gropp et al., GCN 33527
Not found
 
 
;
Fermi GBM detection: Veres et al., GCN 33526
Not found
 
 
). 

The KNC observations were taken by F. Kugel with an ARTEMIS CCD ATIK-460ex 
camera mounted in the 0.4-m f/2.8 reflector telescope in the Chante-Perdrix 
Observatory (France).
The afterglow is detected in the 36x60s unfiltered coadded images at
about 5.2 hours (midtime of the exposure) after the Swift/BAT trigger time.

Below, we report our photometric measurement in Rc magnitude.
-------------------------------------------------------------
T-T0 (day)  |Exposure| Filter | Mag +/- err |Mag.Lim. (AB)
-------------------------------------------------------------
0.22172 | 36 x 60s | Rc | 20.19 +/- 0.10 | 21.4 (3 sigma)

Our detection is consistent with the detections and limits previously reported
in Pankov et al., GCN 33528
Not found
 
 
.; Belkin, GCN 33530
Not found
 
 
; Lu et al., GCN 33534
Not found
 
 
;
Catapano et al., GCN 33535
Not found
 
 
; Suresh et al., GCN 33536
Not found
 
 
.; Adami et al., 
GCN 33537
Not found
 
 
; Gompertz et al., GCN 33538
Not found
 
 
; Komesh et al., GCN 33539
Not found
 
 
;
Lu et al., GCN 33540
Not found
 
 
; Ror et al., GCN 33547
Not found
 
 
; Agui Fernandez et al., GCN 33549
Not found
 
 


The GRANDMA/Kilonova-Cacther images have been calibrated using field
stars from the PanSTARRS-DR1 catalog using the STDpipe pipeline
(Karpov 2022) and the ps1/r to Rc mag conversion from (Pancino et al. 2022).

GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr)
devoted to the observation of transients in the context of multi-messenger
astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is
the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).