GCN Circular 211
D. A. Frail (NRAO), and S. R. Kulkarni (Caltech) report on behalf of a larger NRAO/Caltech collaboration: "We obtained a second VLA observation of the error box of GRB 990123 (GCN #199) beginning on January 24.65 UT at 8.46 GHz. At the location of the optical transient (GCN #201) there is a new radio source with a flux density of 260 +/- 32 microJy. A similar image taken on January 23.63 UT (GCN# 200) gives a 2-sigma upper limit at this same location of 64 microJy. We are likely observing the slow "turn-on" of the afterglow. Further observations are planned to track its expected rise to maximum and its subsequent power-law decay." This message is citeable.