Electronic Telegram No. 1183
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 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://www.cfa.harvard.edu/iau/cbat.html


V459 VULPECULAE
     U. Munari and A. Siviero, Istituto Nazionale di Astrofisica, Padova
Astronomical Observatory; and P. Valisa, A. Frigo, S. Dallaporta, G. Cherini,
and G. Dalla Via "Asiago Novae and Symbiotic Stars" (ANS) collaboration,
report that CCD photometry of this nova (cf. CBET 1181), calibrated on nearby
Tycho-2-catalogue stars, yields the following magnitudes and colors:
Dec. 27.70 UT, V = 7.593, B-V = +1.080; Dec. 27.75, V = 7.576, B-V = +1.101;
Dec. 28.72, V = 7.700, B-V = +1.141.  Absolutely fluxed spectra of the nova
were obtained on Dec. 27.75 and 28.70 with the 1.22-m telescope of the
University of Padova in Asiago and the 0.6-m telescope of the Schiaparelli
Observatory in Varese over the ranges 622-976 nm at 0.16 nm/pixel, 330-800
nm at 0.23 nm/pixel, 622-685 nm at 0.032 nm/pixel, and 560-628 nm at 0.033
nm/pixel.  The spectra on Dec. 27.75 were dominated by the fully developed
absorption spectrum of the expanding, optically thick ejecta, with only
H_alpha and O I 777.2-nm showing a weak emission component flanked by a deep,
unstructured P-Cyg absorption.  The higher Balmer series and Fe II lines
reported in emission on CBET 1181 were gone.  The absorption lines had a
Gaussian shape with a FWHM (corrected for instrumental resolution) of 610
km/s and a velocity of -640 km/s with respect to H_alpha and O I emission
components, which had a FWHM of 750 km/s.  On Dec. 28.70, the spectrum
changed remarkably, indicating that the decline from maximum has probably
begun.  Higher Balmer series lines have turned into emission, together with
N II and Na I D.  H_alpha increased the flux by five times with respect to
the H_alpha on Dec. 27.75, and Fe II displayed a rich emission-line spectrum
composed of multiplets 27, 28, 37, 38, 42, 46, 48, 49, 55, and 74. Overall,
the absorption line spectrum typical of a nova at maximum brightness has
decreased, and almost all of the absorptions still visible are now part of
P-Cyg profiles.  Strong diffuse interstellar bands and Na I interstellar
lines suggest a large reddening, possibly with E(B-V) > 0.7.
     Visual magnitude estimates by A. Pereira, Cabo da Roca, Portugal:
Dec. 26.79 UT, 8.0; 27.79, 7.7.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2007 CBAT
2007 December 28                 (CBET 1183)              Daniel W. E. Green