2003IAUC.8112....3R

M. P. Rupen, A. J. Mioduszewski, and V. Dhawan, National Radio Astronomy Observatory (NRAO), report a strong radio flare from this x-ray transient and blackhole candidate (IAUC 8105). Observations with the Very Large Array (VLA) on Apr. 6 and 8 UT show that the source increased in flux density by almost a factor 5 at 4.9 GHz, from 20.1 ± 0.3 to 96 ± 2 mJy. The radio spectrum also changed significantly, from flattish (optically thick) on Apr. 6 to falling with frequency (optically thin) on Apr. 8, with flux densities varying from 19.5 ± 0.3 to 68 ± 2 mJy at 8.5 GHz, 20 ± 1 to 54 ± 2 mJy at 14.9 GHz, 22 ± 2 to 51 ± 2 mJy at 22.5 GHz, and 17 ± 3 to 42 ± 4 mJy at 43.4 GHz. The Apr. 8 spectrum, in particular, is not well fit by a single power law, in the sense that the flux density is too high at the highest frequencies. This suggests the existence of several overlapping components (e.g., an extended jet and a compact core) and may indicate that another flare is on the way.