Central Bureau for Astronomical Telegrams
IAUC 8821: V2467 Cyg = N Cyg 2007
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Circular No. 8821
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)
V2467 CYGNI = NOVA CYGNI 2007
S. Nakano, Sumoto, Japan, reports the discovery by Akihiko
Tago (Tsuyama, Okayama-ken) of a possible nova (mag 7.4) on three
30-s CCD exposures taken around Mar. 15.787 UT with a Canon 20Da
digital camera (+ 70-mm f/3.2 lens; limiting magnitude 13.2 +/- 0.2),
with Tago giving the position of the variable as R.A. = 20h28m15s,
Decl. = +41o49'.0 (equinox 2000.0), and noting that nothing was
visible at this position on his frame taken on Mar. 12.796
(limiting mag 12). Tago adds that an image taken by himself on Mar.
16.75 shows the variable at mag 7.5. Nakano provides his own
measure of the position end figures (estimated uncertainty perhaps
+/- 5" or more) from Tago's discovery image: 13s.22, 48'45".5,
magnitude 6.8 +/- 0.4. Nakano further adds that K. Nishiyama and T.
Sakamoto, Bisei Spaceguard Center, have confirmed the variable star
at mag 6.7 on an unfiltered CCD image taken with the 1.0-m f/3.0
reflector on Mar. 16.768, giving the object's position end figures
as 12s.52, 48'36".5. A red USNO-catalogued star is located at
position end figures 12s.505, 48'36".69 (red mag 18.5).
K. Ayani, Bisei Astronomical Observatory (BAO), writes that
low-resolution spectra (range 380-800 nm; resolution 0.55 nm at
H_alpha), obtained with the BAO 1.01-m telescope on Mar. 16.8 UT,
show that this variable is a nova. The spectra show Balmer and Fe
II absorption lines on a red continuum. The H_alpha line has a P-
Cyg profile whose absorption bottom is blueshifted by 1200 km/s
with respect to the emission peak.
H. Naito and M. Sakamoto, Nishi-Harima Astronomical
Observatory, report that they obtained a low-resolution spectrogram
(range 410-670 nm; resolution 2000 at H_alpha) of the nova on Mar.
16.792 UT with the 2.0-m NAYUTA telescope (+ MALLS). The spectrum
shows a broad H_alpha line with a P-Cyg profile and Fe II
absorption lines, which suggests that the variable is indeed a
classical nova near maximum light. A narrow Na I D absorption
feature suggests the existence of a considerable interstellar
reddening. The FWHM of the H_alpha emission is 950 km/s, and its
absorption minimum is blueshifted by 1150 km/s from the emission
peak (measured by a Gaussian fitting).
Visual magnitude estimates: Mar. 17.010 UT, 7.9 (K. Hornoch,
Lelekovice, Czech Republic); 17.146, 8.1 (K. Sarneczky, Budapest,
Hungary); 18.453, 7.7 (J. D. West, Mulvane, KS, U.S.A.); 19.012,
8.5 (P. Schmeer, Bischmisheim, Germany).
N. N. Samus, Institute of Astronomy, Russian Academy of
Sciences, informs us that this nova has been given the designation
V2467 Cyg.
(C) Copyright 2007 CBAT
2007 March 19 (8821) Daniel W. E. Green
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