Central Bureau for Astronomical Telegrams
IAUC 8361: 2004cs, 2004ct,, 2004cu; C/2003 K4
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 8362
.dvi or
.ps format.
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
Three 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
Read IAUC 8362
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
