Image of XTE J1859+226 field made from 1.42 GHz VLA data on Oct 12.08 UT. The circle indicates the RXTE PCA error region reported in IAUC 7274 and the + that is merged in with the radio source at the center is at the position of the Garnevich et al. optical counterpart reported in IAUC 7276.
The weak radio source just to the lower right of the PCA error region is the NVSS source often mentioned in E-mail messages. The strong source in the lower right corner is another background source.
The variability of the radio counterpart is clearly established. The data show that the radio source progressed from a slightly optically thick, initial state on Oct. 13.06 UT to a less optically thick source on Oct. 14.11 UT, then decayed, had another flare to 110 mJy, decayed, and story still goes on. The following shows the radio and X-ray light curves. The X-ray data are from the RXE "weather" page, and the radio data are from the Ryle Telescope (sent by Guy Pooley), the GBI, and the VLA.
The initial report on the X-ray source by Wood et. al. and Markwardt et al. was in IAUC 7274, the optical counterpart was reported by Ganavich et al. in IAUC 7276, and the initial report by Pooley and Hjellming on the radio counterpart was in IAUC 7278.
R.M. Hjellming (NRAO), M.P. Rupen (NRAO), A.J. Mioduszewski (University of Sydney), and G.G. Pooley (Mullard Radio Astronomy Observatory)
For more information contact R.M. Hjellming