TITLE: GCN CIRCULAR NUMBER: 41215 SUBJECT: GRB 250702B: SMA observations DATE: 25/08/01 22:24:26 GMT FROM: lauren.rhodes@mcgill.ca

We observed the position of GRB 250702B (GCN #40883, #40886, #40890) with the Submillimeter Array (SMA) at a central frequency 225.5GHz for 4.5hours beginning at 06:51UT on 31 July 2025. Vesta and MWC349A were used as the flux calibrator, while 3C84 was used to calibrate the bandpass response. 1743-038 and 1911-201 were used as interleaved complex gain calibrators.

The data was processed using the COMPASS pipeline (Keating et al, in prep). We do not detect any emission at the position of GRB 250702B (GCN #40924) with a 3sigma upper limit of 0.84mJy/beam.

We thank the staff at the SMA for carrying out these observations.

View this GCN Circular online at https://gcn.nasa.gov/circulars/41215. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...