Electronic Telegram No. 3767 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network COMET C/2012 S1 (ISON) S. Sako, H. Maehara, K. Motohara, S. Nishijima, Y. Kikuchi, and K. Arimatsu, University of Tokyo; K. Ohnishi, Nagano National College of Technology; and Y. Sarugaku, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan, report on their unsuccessful post-perihelion searches for the remnants of comet C/2012 S1, which fell apart near perihelion (cf. CBET 3731, IAUC 9266). Deep CCD searches were made with the Kiso Wide Field Camera (KWFC) + I-band filter on Dec. 7.9 and 16.9 UT, and with a Canon CMOS sensor (unfiltered) on Dec. 12.9 and 13.9, both mounted on the Kiso 1.05-m Schmidt telescope; the field-of-view of the KWFC and the CMOS sensor are 125' x 125' and 22' x 40' (north-south by west-east), respectively. On Dec. 7.9, the area searched spanned 90' x 30'. The table below gives the imaging time, the center of the field-of-view, the offset in right ascension and declination (in degrees) of the image center from the predicted ephemeris position (offset computed by S. Nakano, Sumoto, Japan), and the limiting magnitude. 2013 UT R.A. (2000.0) Decl. Delta Delta Limiting R.A. Decl. magnitude Dec. 7.87 16 11 34.4 -00 49 12 0.00- 0.13+ 14.5 12.84 16 09 52.2 +09 59 42 0.12- 0.55+ 19.0 12.84 16 09 30.6 +10 14 58 0.21- 0.79+ 19.0 12.85 16 09 09.0 +10 30 07 0.30- 1.04+ 19.0 12.85 16 08 47.7 +10 45 23 0.39- 1.28+ 19.0 12.86 16 10 32.0 +09 34 27 0.04+ 0.09+ 19.0 13.83 16 09 55.6 +12 14 16 0.13- 0.47+ 19.0 13.84 16 09 11.9 +12 44 50 0.30- 0.95+ 19.0 13.84 16 08 50.3 +12 59 59 0.39- 1.19+ 19.0 13.85 16 09 30.2 +12 31 37 0.23- 0.71+ 19.0 13.85 16 10 35.1 +11 52 33 0.03+ 0.05+ 19.0 13.86 16 10 13.5 +12 03 41 0.05- 0.22+ 19.0 13.86 16 09 52.2 +12 18 48 0.14- 0.46+ 19.0 13.87 16 09 31.2 +12 33 53 0.23- 0.70+ 19.0 16.88 16 11 31.6 +19 45 05 0.07+ 0.14+ 15.5 Unsuccessful visual searches for the comet, with estimated limiting magnitudes: Dec. 4.26 UT, [8.0 (B. H. Granslo, Roverkollen, Oslo, Norway, 0.08-m refractor; altitude 5 degrees in twilight); Dec. 8.8, [10.6 (Akie Hashimoto, Chichibu, Saitama-ken, Japan, 25x150 binoculars; communicated by S. Nakano, Sumoto, Japan). S. Nakano, Sumoto, Japan, has also reported the following unsuccessful CCD searches for the comet after perihelion, with limiting magnitudes: Dec. 8.85 UT, [16.6 (K. Kadota, Ageo, Japan, 0.16-m f/3.3 hyperbolic astrograph); 8.88, [15 (Katsumi Yoshimoto, Yamaguchi, Japan, 16-cm reflector); 10.85, [17.2 (Kadota); 12.86, [17 (Y. Ikari, Moriyama, Shiga-ken, Japan, 0.26-m reflector); 14.86, [15.5 (Yoshimoto, Nikon digital camera + 180-mm f/2.8 lens). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2013 CBAT 2013 December 29 (CBET 3767) Daniel W. E. Green