[vsnet-grb-info 25248] GRB 200306C: Calar Alto 2.2m upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27348
SUBJECT: GRB 200306C: Calar Alto 2.2m upper limit
DATE:    20/03/08 07:43:45 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann at iaa.es>

D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, 
DARK/NBI), M. Blazek, C. C. Thoene, J. F. Agui Fernandez (all 
HETH/IAA-CSIC), R. Pedro Hedrosa, and E. Gallego (both CAHA) report:

We observed the field of the afterglow of GRB 200306C (Lipunov et al., 
GCNs #27324, #27325; Gropp et al., GCN #27326; Jelinek et al., GCN 
#27328; Hu et al., GCN #27329; Moskvitin, GCN #27333; Izzo &
Perley, GCN #27334; Kann et al., GCN #27335; Steele et al., GCN #27338) 
with the 2.2m telescope of Calar Alto equipped with CAFOS. We obtained 4 
x 720 s images in the Rc band under adverse conditions (moonlight, 
passing clouds, bright star still there).

Our stacked image centred at mean epoch 1.25519 d after the GRB shows no 
detection to a 3-sigma upper limit of Rc > 23.0 mag (AB). The magnitude 
limit was obtained versus SDSS stars in the field.