Electronic Telegram No. 1319 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2008bk IN NGC 7793 W. Li, University of California, Berkeley (UCB); S. D. Van Dyk, Spitzer Science Center, California Institute of Technology; A. V. Filippenko and R. J. Foley, UCB; G. Pignata, M. Hamuy, and J. Moza, Universidad de Chile; and D. Reichart, K. Ivarsen, A. Crain, D. Foster, M. Nysewander, and A. LaCluyze, University of North Carolina at Chapel Hill, report that they have analyzed the discovery images of SN 2008bk that were taken by Monard (cf. CBET 1315) and also images taken with the 0.41-m "PROMPT 2" telescope at Cerro Tololo on Mar. 28.41 UT. Using half a dozen stars for an astrometric solution, they derive the following precise position for 2008bk: R.A. = 23h57m50s.42, Decl. = -32d33'21".5 (equinox 2000.0), which is 9".2 east and 126".4 north of the nucleus of NGC 7793. Li et al. have further applied their astrometric solution to deep archival ground-based images taken with the Very Large Telescopes (VLT). Within the uncertainty of the solution (0".2 error radius), they identified a single point source on an I-band image taken on 2001 Sept. 16 UT, which Li et al. propose as the possible progenitor for SN 2008bk. The source is not detected in the B- and V-band images, so it is a red source [likely a red supergiant (RSG) star]. The possible progenitor of 2008bk also resides in a cluster of bright blue and red supergiant stars. Based on the environment of SN 2008bk and its possible progenitor identification, Li et al. postulate that 2008bk is a core collapse (likely a type-II) event. Further analysis on the astrometry and photometry of the progenitor star is on-going. A finder chart for the possible progenitor can be found at the following website URL: http://astro.berkeley.edu/~weidong/sn2008bk.vlt-prog.gif G. Pignata, J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, P. Gonzalez, P. Lopez, S. Silva, and G. Folatelli, Universidad de Chile; and D. Reichart, K. Ivarsen, A. Crain, D. Foster, M. Nysewander, and A. LaCluyze, University of North Carolina at Chapel Hill, on the behalf CHASE project, report that images taken with the "PROMPT2" and "PROMPT4" telescopes yield the following magnitudes (+/- 0.05) for 2008bk: Mar. 28.41 UT, B = 12.78, V = 13.05 (indicating B-V = -0.27); Mar. 29.40, B = 12.79, V = 13.02. The calibration star is listed in the Tycho-2 catalogue (at R.A. = 23h57m53s.03, Decl. = -32o32'42".9; B = 12.499, V = 12.476). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 March 30 (CBET 1319) Daniel W. E. Green