TITLE:   GCN CIRCULAR
NUMBER:  27807
SUBJECT: GRB 200524A: CAHA multicolor afterglow detection
DATE:    20/05/24 23:38:09 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

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

We observed the field of GRB 200524A (Fermi-LAT detection: Dirirsa et 
al. GCN #27797) with CAFOS, on the 2.2 m telescope, at Calar Alto 
observatory (Almeria, Spain). Observations consisted of 3 x 500 s in 
BVRc each, and 8 x 180 s in Ic-band.

The afterglow (Ho et al., GCN #27799, Kumar et al., GCN #27800, 
Rumyantsev et al., GCN #27802, Sanwal et al., GCN #27803, Perley et al., 
GCN #27805, Kumar et al., GCN #27806) is well-detected in each image. In 
an Rc image starting at 21:49:33 UT (mid-time 0.701188 days after the 
Fermi GBM trigger), we measure Rc = 20.86 +/- 0.12 mag (Vega mags) 
against five nearby SDSS stars transformed to the Rc band.