From quai@cbatmpc.harvard.edu Thu Jun 18 19:27:18 1998 Return-Path: Received: [ from aip.de by abrixas.obs.aip.de (8.8.7/8.8.7) with SMTP id TAA32626 for ; Thu, 18 Jun 1998 19:27:16 +0200 (MET DST)] Received: from cfa.harvard.edu by marlowe (4.1/SMI-4.2-apr170795) id AA24882; Thu, 18 Jun 98 19:26:54 MES Received: from cbatmpc.harvard.edu (cbatmpc.harvard.edu [131.142.10.57]) by cfa.harvard.edu (8.8.5/8.7.3) with SMTP id NAA27630 for ; Thu, 18 Jun 1998 13:26:53 -0400 (EDT) Received: by cbatmpc.harvard.edu (SMI-8.6/SMI-SVR4) id NAA21170; Thu, 18 Jun 1998 13:26:54 -0400 Date: Thu, 18 Jun 1998 13:26:54 -0400 From: quai@cbatmpc.harvard.edu (IAUC mailing list) Message-Id: <199806181726.NAA21170@cbatmpc.harvard.edu> To: iau-circulars@aip.de Subject: IAUC 6944: 1998cn; SGR 1627-41 Status: RO Circular No. 6944 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 Phone 617-495-7244/7440/7444 (for emergency use only) SUPERNOVA 1998cn IN NGC 3735 Michael Schwartz, Cottage Grove, OR, reports his discovery of an apparent supernova (mag 15.8) on an unfiltered CCD frame taken with the 0.35-m Tenagra I automated supernova patrol telescope on June 17.48 UT. SN 1998cn is located at R.A. = 11h35m54s.4, Decl. = +70o32'10".2 (equinox 2000.0), which is 5".6 west and 10".2 north of NGC 3735. The object is also present with unchanged brightness on a frame taken on June 18.26. The object does not appear on an unfiltered CCD image taken with the same equipment on Apr. 17.31, and the star is not present in the Vickers atlas and other CCD atlases. SGR 1627-41 C. Kouveliotou, Universities Space Research Association (USRA); M. Kippen, P. Woods, and G. Richardson, University of Alabama in Huntsville; V. Connaughton, National Research Council; and M. McCollough, USRA, report on behalf of the BATSE team at Marshall Space Flight Center, NASA: "BATSE has detected repeated soft gamma-ray bursts consistent with the same (previously unknown) location. We recorded three bursts on June 15.109, 15.296, and 15.411 UT (BATSE triggers 6825, 6826, and 6827, respectively) with an average duration of about 200 ms. Preliminary spectral analysis of the data indicates that the events are very soft, with power-law spectral indices varying between -3.0 and -7.0. BATSE triggered five more times, on June 17.873, 17.901, 18.004, 18.035, and 18.071 (BATSE trigger numbers 6833, 6834, 6835, 6836, and 6837, respectively). The last trigger had a peak count rate of over 300 000 counts/s above background (integrated over four detectors between 20 and 1000 keV, in 1-s intervals) and a duration of about 3 s. Due to its very high peak intensity, deadtime effects prevent us from using it for localization, until we receive more data types. The weighted location of the seven remaining triggers is centered on R.A. = 16h27m12s, Decl. = -41o06'.0, with an error radius of about 2 deg. This location does not correspond to any previously known soft gamma-ray repeating source; we conclude that we have discovered a new source, SGR 1627-41. We have initiated an RXTE ToO and we strongly encourage wide-field observations at other wavelengths." (C) Copyright 1998 CBAT 1998 June 18 (6944) Daniel W. E. Green