SIMBAD references

M. P. Rupen, National Radio Astronomy Observatory (NRAO); C. Brocksopp, Mullard Space Science Laboratory; A. J. Mioduszewski, V. Dhawan, NRAO; R. Sault, Australia Telescope National Facility; R. Fender, University of Amsterdam; and S. Corbel, University of Paris and Laboratoire du Commissariat a l'Energie Atomique, Saclay, report the detection of a radio counterpart of XTE J1720-318 (IAUC 8050). Observations were made with the Very Large Array (VLA) on Jan. 15 UT, and with the Australia Telescope Compact Array on Jan. 16. There are several radio sources within the x-ray error circle, but only one of these has varied significantly, rising at 4.9 GHz from 0.32 ± 0.04 mJy on Jan. 15 to 4.9 ± 0.1 mJy on Jan. 16. The VLA data give a position of R.A. = 17h19m59s.062 ± 0s.087, Decl. = -31o44'59".7 ± 1".10 (equinox 2000.0), about 1'.4 from the original x-ray position. Further VLA data from Jan. 15 give a flux density at 8.5 GHz of 0.27 ± 0.06 mJy, and a non-detection at 1.4 GHz (rms of 0.24 mJy/beam). The Northern VLA Sky Survey (Condon et al. 1998, A.J. 115, 1693) also show no source at 1.4 GHz in 1995, to an rms noise limit of 0.52 mJy/beam. Further radio observations are planned, and observations at other wavelengths are urgently requested.