Circular No. 5395 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Telephone 617-495-7244/7440/7444 (for emergency use only) TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505 MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN GX 339-4 G. J. Fishman, B. A. Harmon, B. Rubin, M. H. Finger, R. B. Wilson, W. S. Paciesas, and C. A. Meegan, Marshall Space Flight Cen- ter, NASA, report for the BATSE Experiment Team: "Hard x-ray/gamma- ray fluxes from the black hole candidate GX 339-4 have been moni- tored daily by earth occultation for several months, except for about 6-day periods when the source is not occulted. The source was reported previously to exhibit a significant brightening (IAUC 5327, 5352) between 20 and 230 keV. This brightening period lasted about 2 months (June 25-Aug. 22), with the source remaining at 380 mCrab (20-230 keV) until Sept. 22. The spectrum appears to extend to energies of at least 430 keV. Between Sept. 22 and Oct. 1, flux from GX 339-4 dropped below the current BATSE one-day sensitivity level (about 0.1 Crab), with no significant flux detected as of Nov. 15." GALACTIC CENTER I. F. Mirabel, Service d'Astrophysique, Saclay; L. F. Rodriguez, Universidad Nacional Autonoma de Mexico; and B. Cordier, J. Paul, and F. Lebrun, Saclay, communicate: "We report preliminary results from Very Large Array observations at 3.6, 6, and 20 cm, coordinated with SIGMA and the Gamma Ray Observatory, during the following dates: 1991 Sept. 3, 7, Oct. 3, 7. We have also analysed the VLA archive data obtained in 1989 March by Kulkarni and Prince (IAUC 5252). Within the Einstein and SIGMA error circles of 1E 1740.7-2942, two sources were present in 1989: source 'A' (R.A. = 17h40m42s.99, Decl. = -29 43'25", equinox 1950.0) and source 'B' (R.A. = 17h40m42s.45, Decl. = -29 43'05"). Source 'B' is double, has a non-thermal spec- trum, and is likely to be a background radio galaxy. Source 'A' is time variable; it was detected in 1991 October with a flux of 0.15 mJy at 6 cm, which is about 3 times lower than the flux observed in 1989. Our data suggest that the source was below 0.1 mJy in 1991 August and September. These variations in the radio flux are con- sistent with those observed from 1E 1740.7-2942 by SIGMA during the last year (IAUC 5204). Because of this variability we confirm that the source 'A' is the radio counterpart of 1E 1740.7-2942." 1991 December 2 Daniel W. E. Green