TITLE:   GCN CIRCULAR
NUMBER:  40591
SUBJECT: GRB 250530C: BOOTES-7 optical upper limit
DATE:    25/05/31 17:31:45 GMT
FROM:    I. Perez-Garcia at Institute of Astrophysics of Andalusia <ipg@iaa.es>

I. Perez-Garcia, E. Fernandez-Garcia, S.-Y. Wu, M. D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy, and A. J. Castro-Tirado (IAA-CSIC, Granada), C. Perez del Pulgar (Univ. of Malaga), L. Hernandez-Garcia (Univ. of Valparaiso), M. Gritsevich (Univ. of Helsinki), Y.-D. Hu (GXU), B.-B. Zhang (Nanjing Univ.), and A. Maury (Space Obs., San Pedro de Atacama), on behalf of a larger collaboration, report:

Following the detection of GRB 250530C by Swift (Osborne et al., GCNC [40586](https://gcn.nasa.gov/circulars/40586)), the 0.6m BOOTES-7 robotic telescope at Space Observatory (San Pedro de Atacama, Chile) automatically responded to this high-energy event starting on May 21, 09:42:59 UT (i.e., 14.73 hour after detection), observing at low elevation (airmass ≈ 5). No optical transient is detected down to 16.4 mag (clear filter). On a coadd (11) of images at 09:51:43 UT (mid exposure time; i.e. 14.88 post burst), nothing is detected down to 18.2 mag.

We would like to thank the staff at San Pedro de Atacama Space Observatory for their excellent support.