TITLE:   GCN CIRCULAR
NUMBER:  44941
SUBJECT: GRB 260610B: ALMA detection
DATE:    26/06/14 21:57:00 GMT
FROM:    Tanmoy Laskar at U of Utah <tanmoylaskar@gmail.com>

T. Laskar (Utah), B. P. Gompertz (Birmingham), G. E. Anderson (Curtin), A. Levan (Radboud and Warwick), Daniele Malesani (DAWN/NBI and Radboud), Steve Schulze (Weizmann), Nial Tanvir (Leicester), A. J. van der Horst (GWU) report on behalf of a larger collaboration:

“We observed GRB 260610B (Fermi GBM team, GCN 44891; O'Neill et al., GCN 44903) with the Atacama Large Millimeter/Submillimeter Array (ALMA) at 43 GHz beginning on 2026 June 13 at 01:06 UT (2.62 days after the burst).

Preliminary analysis reveals a mm source with flux density of ~ 0.3 mJy at position:

RA (J2000) = 14:32:38.2
Dec (J2000) = +27:00:17.6

with an uncertainty of 0.2" in each coordinate. This is consistent with the optical position (O'Neill et al., GCN 44903). Further observations are planned.

We thank the P2G, AoD, JAO staff, and the entire ALMA team for their help with these observations."