Central Bureau for Astronomical Telegrams
IAUC 8702: 73P; V2362 Cyg
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Circular No. 8702
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)
COMET 73P/SCHWASSMANN-WACHMANN
S. N. Milam, A. J. Apponi, L. M. Ziurys, and S. Wyckoff,
Arizona Radio Observatory and Steward Observatory, report that
observations of the J = 1-0 transition of HCN at 88.6 GHz were
conducted towards component 'C' of comet 73P on Apr. 11.36 UT with
the Arizona Radio Observatory 12-m telescope on Kitt Peak. Two out
of three hyperfine components were detected with intensities of
0.035 +/- 0.005 K for the F = 2-1 transition and 0.024 +/- 0.006 K
for the F = 1-1 line, with corresponding line widths of 1.0 +/- 0.2
and 0.7 +/- 0.2 km/s, respectively. These measurements indicate a
total column density of about 3.4 x 10**11 cm**-2 for HCN in the
'C' source of 73P. A production rate of Q(HCN) about 3.05 x 10**25
s**-1 [correction to CBET 474] was calculated using a Monte Carlo
model, assuming that this molecule is a parent species arising from
the nucleus. This transition of HCN appears at the cometocentric
velocity derived from the JPL Horizons ephemeris.
V2362 CYGNI
A. Siviero, U. Munari, and M. Valentini, INAF, Padova-Asiago;
and P. Valisa, Centro Geofisico Prealpino, report that high-
dispersion spectra (range 370-730 nm; resolving power 21000) of
V2362 Cyg (cf. IAUC 8697, 8698) were obtained on Apr. 13.1 UT with
the Asiago 1.82-m telescope; low-dispersion spectra (range 410-700
nm; dispersion 0.17 nm/pixel) were obtained about the same time
with the 0.6-m telescope of the Schiapparelli Observatory in Varese.
The nova belongs to the 'Fe II class' in showing prominent Fe II
emission lines from multiplets 27, 37, 38, 42, 48, 49, and 74 -- in
addition to [O I] at 557.7, 630.1, and 636.4 nm, and also Na I and
Balmer series lines. H_alpha and H_beta display a very broad and
structured profile with FWZI = 3750 km/s and FWHM = 1800 km/s. The
interstellar Na I D in absorption shows two narrow components (FWHM
20 km/s) at radial velocities -39 and -11 km/s; their equivalent
widths correspond, via a Munari and Zwitter (1997, A.Ap. 318, 269)
calibration, to a total reddening of the nova of E(B-V) = 0.56.
H. Yamaoka, Kyushu University, reports the following precise
position for V2362 Cyg using UCAC2-catalogue stars: R.A. =
21h11m32s.346 +/- 0s.010, Decl. = +44o48'03".66 +/- 0".14 (equinox
2000.0; details on CBET 466). The nearby "red" star mentioned on
IAUC 8697 has UCAC2 position end figures 31s.884, 3".23. The DSS
blue (1993 June 27) and red (1990 Sept. 10) images show a dimmer
object (red mag about 18) near the nova's position; if it is a true
progenitor, the amplitude of nova outburst is about 10 magnitudes.
(C) Copyright 2006 CBAT
2006 April 13 (8702) Daniel W. E. Green
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