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IAUC 8360: 2004ci, 2004cr; C/2001 Q4

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                                                  Circular No. 8360
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 2004ci AND 2004cr
     R. J. Foley, M. Ganeshalingam, and A. V. Filippenko,
University of California, report that CCD spectra (range 330-1000
nm), obtained on June 20 UT with the Shane 3-m telescope at Lick
Observatory, show that SNe 2004ci (IAUC 8357) and 2004cr (IAUC
8359) are both of type II.  The expansion velocities, derived from
the minimum of H_beta for SNe 2004ci (recession velocity 4158 km/s
from narrow H_alpha) and 2004cr (recession velocity 5055 km/s from
narrow H_alpha), are 11813 and 8443 km/s, respectively.
     T. Matheson, P. Challis, and R. Kirshner, Harvard-Smithsonian
Center for Astrophysics, report that a spectrum (range 340-730 nm)
of SN 2004ci, obtained by E. Adams and M. Westover on June 19.23 UT
with the Mt. Hopkins 1.5-m telescope (+ FAST spectrograph), shows
it to be a type-II supernova.  The spectrum consists of a blue
continuum with P-Cyg lines of hydrogen and helium.  Adopting the
NASA/IPAC Extragalactic Database recession velocity of 4092 km/s
for the host galaxy, the expansion velocity derived from the
minimum of the H_beta line is 10700 km/s.


COMET C/2001 Q4 (NEAT)
     Further to IAUC 8358, R. W. Russell, D. L. Kim, M. L. Sitko,
and W. J. Carpenter, report additional 3-13-micron
spectrophotometry of C/2001 Q4, obtained on June 20.2 UT at Mt.
Lemmon (integration time 45 min; reference star alpha Boo):  "A
smooth comet continuum was seen to rise from 3.5 to 8.4 microns,
beyond which a moderate silicate emission band was observed.  An
underlying blackbody continuum with a temperature of about 315 +/-
5 K was fit to the continuum flux at 5, 8.4, and 12 microns.  This
grain temperature is about 21 +/- 2 percent higher than that of an
equilibrium blackbody at the heliocentric distance of the comet.
The silicate-feature-to-continuum ratio was 1.32 +/- 0.02 --
slightly greater than the value of 1.26 reported on June 17.2 (IAUC
8358), but still significantly less than that reported on May 31.2
(1.43; IAUC 8351) and May 14.2 (1.65; IAUC 8342). The crystalline
olivine feature at 11.2 microns continues to be present with
approximately the same contrast as originally seen.  With our
aperture, the comet has the following narrowband (about 0.25 micron)
magnitudes and combined random errors:  [3.7 microns] = 7.73 +/-
0.17, [4.7 microns] = 5.49 +/- 0.20, [5 microns] = 4.95 +/- 0.23,
[8 microns] = 2.10 +/- 0.18, [10.5 microns] = 0.50 +/- 0.05, [12
microns] = 0.26 +/- 0.04."
     Visual total-magnitude estimates:  June 8.89 UT, 6.6 (W.
Hasubick, Buchloe, Germany, 10x50 binoc.); 19.93, 6.4 (A. Diepvens,
Balen, Belgium, 20x50 binoc.); 21.92, 6.7 (J. J. Gonzalez,
Asturias, Spain, 7x50 binoc.).

                      (C) Copyright 2004 CBAT
2004 June 23                   (8360)            Daniel W. E. Green

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