TITLE: GCN CIRCULAR NUMBER: 15680 SUBJECT: GRB 131231A: CARMA 3mm detection DATE: 14/01/05 01:15:53 GMT FROM: Daniel Perley at Caltech D. A. Perley (Caltech) reports on behalf of a larger collaboration: We observed the position of GRB 131231A (Sonbas et al., GCN 15640; Jenke and Xiong, GCN 15644) with the Combined Array for Research in Millimeter Astronomy between 2013-01-01 23:54:54 UT and 2013-01-02 02:02:17 UT (1.798-1.887 days post-GRB) at a mean frequency of ~93 GHz, under good conditions. We identify a weak source consistent with the optical localization (Xu et al., GCN 15651; Singer et al., GCN 15643) in the reduced map. The afterglow flux at this time is measured to be 0.85 +/- 0.25 mJy. We thank observers B. A. Zauderer and M. Balokovic and the CARMA staff for executing the observation.