[IAUC] CBET 739: 20061114 : V2362 CYGNI

[IAUC mailing list]

                                                  Electronic Telegram No. 739
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS en CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT en CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html


V2362 CYGNI
     U. Munari, A. Siviero, and H. Navasardyan, Istituto Nazionale di
Astrofisica, Padova Astronomical Observatory; and P. Valisa, G. Dalla Via,
G. Cardarelli, G. Cherini, S. Dallaporta, S. Moretti, S. Tomaselli, P.
Ochner, A. Frigo, and S. Tomasoni, ANS ("Asiago Novae and Symbiotic stars")
Collaboration, write that intensive monitoring carried out with the Asiago
1.82-m telescope and other telescopes operated by the ANS Collaboration
shows that V2362 Cyg (N Cyg 2006) is further developing along the peculiar
behavior described in CBET 671.  Following the minimum brightness of B =
12.25 reached around July 21 (when the colors were B-V = +0.16, V-I_c=
+1.25, and R_c-I_c = +0.02), the nova continues its smooth re-brightening
that has brought it to B = 11.18, B-V = +0.36, V-I_c = +1.10, and R_c-I_c =
+0.42 by Nov. 12.8 UT -- i.e., at the same brightness level that the nova
had around April 23, two weeks past maximum.  The mean re-brightening rates
over the last 20 days have been -0.025, -0.030, -0.028, and -0.038 mag/day
for B, V, R_c, and I_c, respectively.  A major change occurred in the
optical spectra over the last two weeks, with the reappearance on the
Balmer-emission-line profiles of the two strong and blue-shifted absorption
components that were visible for only a few days around maximum brightness,
which had disappeared soon after; on Apr. 8.12, they were located at
heliocentric velocities -1805 and -825 km/s, but in Nov. 5.76 spectra, they
reappeared at -2215 and -931 km/s with equivalent widths of 0.84 and 0.22
nm and FWHM of 0.86 and 0.35 nm, respectively.  These absorption components
had not been present in spectra secured on Oct. 27.  The most recent
spectra obtained on Nov. 13.88 show the emission line profiles to be still
very similar to those of Nov. 5.76.
     Visual magnitude estimates:  Apr. 6.163 UT, 8.3 (P. Schmeer,
Bischmisheim, Germany); 6.965, 8.6 (K. Hornoch, Lelekovice, Czech Rep.);
9.442, 8.5 (J. D. West, Mulvane, KS); 9.99, 9.3 (M. Reszelski,
Szamotuly-Galowo, Poland); 10.424, 9.7 (West); 16.922, 10.1 (S. Shurpakov,
Baran, Belarus); 18.424, 10.5 (West); 26.072, 10.8 (M. Lehky, Hradec
Kralove, Czech Republic); May 4.000, 11.5 (Lehky); 13.010, 11.5 (Lehky);
Sept. 5.833, 12.0 (Lehky); 11.812, 12.1 (Lehky); 20.833, 12.2 (Lehky);
26.781, 12.0 (Lehky); 29.795, 12.1 (Lehky); Oct. 8.784, 11.9 (Lehky);
14.87, 12.1 (J. Carvajal, Madrid, Spain); 16.777, 11.8 (Lehky); 19.812,
11.9 (Lehky).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2006 CBAT
2006 November 14                 (CBET 739)               Daniel W. E. Green