Circular No. 7221 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304 Phone 617-495-7244/7440/7444 (for emergency use only) GRB 990712 J. Heise and J. in 't Zand, Space Research Organization of the Netherlands, Utrecht; G. Tarei and V. Torroni, BeppoSAX Science Operation Center, Telespazio, Rome; M. Feroci and G. Gandolfi, Istituto di Astrofisica Spaziale, CNR, Rome; and E. Palazzi, Istituto Tecnologie e Studio Radiazioni Extraterrestri, Bologna, report: "A gamma-ray burst of moderate intensity, with the strongest x-ray counterpart observed to date, triggered the BeppoSAX Gamma-Ray Burst Monitor on July 12.69655 UT and was simultaneously detected in the Wide Field Camera (WFC) unit 2. The burst lasted for about 30 s in both the gamma-ray (40-700 keV) and x-ray (2-26 keV) energy ranges and has a double-peaked structure. The WFC-determined position of the x-ray counterpart to GRB 990712 is R.A. = 22h31m50s, Decl. = -73o24'.4 (equinox 2000.0), with an error radius of 2' (99-percent confidence level). Due to sun constraints, BeppoSAX cannot perform a follow-up observation with the Narrow Field Instruments." COMET C/1998 T1 (LINEAR) Ephemeris from the orbital elements on MPEC 1999-M35: 1999 TT R. A. (2000) Decl. Delta r Elong. Phase m1 July 1 19 57.53 -44 38.0 0.490 1.470 153.1 18.2 8.1 11 16 12.50 -43 41.3 0.574 1.485 136.1 28.4 8.5 21 14 39.72 -32 49.5 0.836 1.512 109.1 39.4 9.4 31 14 07.33 -26 26.9 1.151 1.552 91.3 40.8 10.2 Aug. 10 13 53.87 -22 56.9 1.474 1.603 77.8 38.2 10.9 20 13 48.23 -20 55.9 1.787 1.663 66.4 33.9 11.5 30 13 46.48 -19 44.2 2.081 1.732 56.0 28.9 12.0 Sept. 9 13 46.93 -19 02.3 2.351 1.807 46.2 23.7 12.4 19 13 48.73 -18 39.5 2.594 1.888 36.8 18.6 12.8 Total visual magnitude estimates: July 8.52 UT, 9.2 (M. Mattiazzo, Wallaroo, South Australia, 0.20-m reflector); 9.39, 8.4 (S. T. Rae, Palmerston North, New Zealand, 0.11-m reflector); 10.31, 9.5 (N. Biver, Oahu, HI, 0.26-m reflector); 11.90, 8.6 (J. G. de S. Aguiar, Campinas, Brazil, 11x80 binoculars); 13.54, 8.5 (Rae, 10x50 binoculars). (C) Copyright 1999 CBAT 1999 July 13 (7221) Daniel W. E. Green