Circular No. 6481 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams 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) Phone 617-495-7244/7440/7444 (for emergency use only) GRB 960720 T. Murakami, R. Shibata, H. Inoue, and F. Nagase, Institute of Space and Astronautical Science; A. Yoshida, N. Kawai, C. Otani, and F. Tokanai, Institute of Physical and Chemical Research; and J. Heise, Space Research Organization of the Netherlands, Utrecht, report on behalf of the ASCA team: "We observed the error region of the SAX-BATSE gamma-ray burst (IAUC 6467) with ASCA on Sept. 19 with a net exposure of 26~000 s. Only one weak x-ray source was detected within the SAX-WFC error region, whose location is consistent with the reported x-ray source of the ROSAT all-sky survey (IAUC 6469), to an accuracy of within 1' radius. The observed GIS countrate (0.7-10 keV) was very weak, (2.8 +/- 0.6) x 10E-3 count/s. Assuming a power-law model with index -2, and a galactic absorption toward this direction of 2.5 x 10E20 cmE-2, the observed flux was 1 x 10E-13 erg cmE-2 sE-1 in the band 0.5-2 keV and 2 x 10E-13 erg cmE-2 sE-1 in the band 0.5-10 keV. The flux at 0.5-2 keV is roughly consistent with the flux observed with ROSAT before the burst that occurred during 1990 Aug. 22-28 (IAUC 6469)." Corrigenda to IAUC 6480. Line 22, for (2.5 +/- 0.5) read (0.9 +/- 0.2). Line 27, for about 1 x 10E-13 read about 4 x 10E-14. Line 28, for 1 and 3 x 10E-13 read 5 and 10 x 10E-14. COMET C/1996 E1 (NEAT) Continuation to ephemeris on IAUC 6440, from orbital elements by B. G. Marsden on MPC 27882: 1996 TT R. A. (2000) Decl. Delta r Elong. Phase m1 Oct. 4 19 19.25 +48 19.5 1.196 1.683 99.7 35.9 11.2 9 19 30.85 +40 59.8 1.242 1.725 100.1 34.7 11.3 14 19 40.63 +34 14.0 1.307 1.768 99.4 33.8 11.6 19 19 49.25 +28 10.1 1.390 1.813 97.6 33.0 11.8 24 19 57.07 +22 50.3 1.486 1.859 95.0 32.2 12.1 29 20 04.33 +18 13.1 1.594 1.906 91.9 31.4 12.3 Nov. 3 20 11.19 +14 14.4 1.711 1.953 88.4 30.5 12.6 8 20 17.74 +10 49.7 1.835 2.002 84.6 29.5 12.8 13 20 24.08 + 7 54.4 1.963 2.051 80.7 28.4 13.1 18 20 30.25 + 5 24.2 2.094 2.100 76.7 27.3 13.3 23 20 36.27 + 3 15.3 2.227 2.150 72.7 26.0 13.6 (C) Copyright 1996 CBAT 1996 October 2 (6481) Daniel W. E. Green