IAU 8361
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                                                  Circular No. 8361



 
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) 
CBAT@CFA.HARVARD.EDU (science) 
URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304 
Phone 617-495-7440/7244/7444 (for emergency use only)

SUPERNOVAE 2004cs, 2004ct, AND 2004cu 
Two apparent supernovae have been discovered on unfiltered CCD 
images: SNe 2004cs and 2004cu by LOSS/KAIT (via W. Li and D. 
Singer; cf. IAUC 8357), and SN 2004ct by T. Boles (cf. IAUC 8343).
SN 2004 UT R.A. (2000.0) Decl. Mag. Offset 
2004cs June 23.42 17 50 14.38 +14 16 59.5 18.0 10".4 E, 15".2 S 
2004ct June 22.01 15 43 45.75 +28 24 59.5 17.5 4".1 W, 4".4 N 
2004cu June 24.28 14 18 29.82 +12 53 03.0 18.8 27".1 E, 3".5 N
Additional approximate magnitudes, from images by the respective 
discoverers unless otherwise noted: SN 2004cs in UGC 11001, June 
21.36 UT, [19.0; 24.20, 17.8. SN 2004ct in MCG +05-37-17, Mar. 20, 
[19.5; May 16, [19.5; 24.201, 17.5 (KAIT). SN 2004cu in NGC 5550, 
May 17.36, [20.0; June 12.33, 19.3 (marginal detection). Boles 
adds that SN 2004ct is not present on Digitized Sky Survey red 
(1989) or blue (1993) plates.

COMET C/2003 K4 (LINEAR) 
Further to IAUC 8358, R. W. Russell, D. L. Kim, M. L. Sitko, 
and W. J. Carpenter report 3-13-micron spectrophotometry of comet 
C/2003 K4, obtained on June 20.3 UT at Mt. Lemmon (integration 
times 90 min on the comet; reference star alpha Boo): "A continuum, 
smooth to within the signal-to-noise, was seen to rise from 3.5 to 
8 microns, beyond which a weak silicate emission band may have been 
observed. An underlying blackbody continuum with a temperature of 
about 235 +/- 10 K was fit to the continuum fluxes at 8.4 and 12 
microns. This grain temperature is about 22 +/- 5 percent higher 
than that of an equilibrium blackbody at the comet's heliocentric 
distance. Using the same wavelength region (10.34-10.71 microns) 
as for other, brighter comets in order to calculate a silicate- 
feature-to-continuum ratio, the possible silicate feature was about 
1.10 +/- 0.05 times higher than the continuum, with the silicate- 
feature-to-continuum ratio > 1. The comet showed the following 
narrowband (about 0.25 micron) magnitudes and combined random 
errors: [8.0 microns] = 4.25 +/- 0.10; [10.5 microns] = 2.41 +/- 
0.06; [12 microns] = 1.76 +/- 0.06. Due to the low flux level of 
the comet and the weakness of its silicate feature, no structure 
due to crystalline material was discernible." 
    Visual total-magnitude estimates: May 12.96 UT, 10.6 (A. 
Baransky, Bucha, Ukraine, 0.20-m refl.); 24.98, 9.8 (A. Diepvens, 
Balen, Belgium, 0.15-m refractor); June 7.96, 8.8 (K. Hornoch, 
Lelekovice, Czech Rep., 10x80 binoc.); 21.93, 8.0 (J. J. Gonzalez, 
Asturias, Spain, 7x50 binoc.).
                       
                       (C) Copyright 2004 CBAT 
            2004 June 24       (8361)       Daniel W. E. Green