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AAVSO Alert Notice 419: Nova eruption in V407 Cyg AAVSO HOME > publications > alert notice

AAVSO Alert Notice 419

Nova eruption in V407 Cyg
March 15, 2010

According to CBET 2199, 2204, and 2205, the suspected symbiotic star
V407 Cyg has been observed in an anomalously bright outburst, and
subsequent spectroscopic observations by multiple observers show clear
signs of a classical nova.  Observations of this anomalous event are
requested immediately, and observers are asked to continue observing
this object until it returns to its previous quiescent level.

The following observations were reported via CBET 2199, 2204, and 2205
(D.W.E. Green, editor; please see those issues of CBET for complete

V407 Cyg was discovered in a bright outburst on 2010 March 10.797 (JD
2455266.297) by K. Nishiyama (Fukuoka, Japan) and F. Kabashima (Saga,
Japan) at an unfiltered magnitude of 7.4 obtained with a 105-mm camera
lens.  They then confirmed the observation using a 0.4-meter reflector,
finding the object at an unfiltered magnitude of about 6.9.  The object
was independently discovered in outburst by the following observers: T.
Kojima (Tsumagoi, Agatsuma-gun, Gunma-ken, Japan) at approximately
magnitude 7 (measured at magnitude 7.3 by S. Nakano) on an image taken
with a Canon EOS 40D camera on 2010 March 11.789 (JD 2455267.289); K.
Sakaniwa (Higashichikumagun, Nagano, Japan) at magnitude 7.4 on images
taken with a 70-mm Canon digital camera on 2010 March 11.8 (2455267.3);
A. Tago (Tsuyama, Okayama-ken, Japan) at approximately 7th magnitude on
images taken 2010 March 11.815 (2455267.315).

Subsequent spectroscopy by Munari et al on 2010 March 13.09 (JD
2455268.59) indicates a peculiar composite spectrum with evidence for a
classical nova in progress, namely broad emission lines with FWHM of
2300 km/s.  Such high velocities cannot occur in symbiotic stars, and so
the current eruption appears to be a nova outburst in progress.  Low
resolution spectra also showing signs of a nova eruption were obtained
by the following observers: K. Imamura (Okayama University of Science,
Okayama, Japan) on 2010 March 13.793; M. Fujii (Okayama, Japan) on March
13.793; H. Maehara (Kwasan Observatory, Kyoto University, Kyoto, Japan)
on March 13.842.

In summary, the evidence points to a classical nova eruption of a
symbiotic star.  The system is further complicated by the fact that the
donor star in the system is likely a variable of Mira type.  All
observations of this complex and interesting system, including visual
estimates, CCD time series, and multicolor photometry are strongly

The following observations have been submitted to the AAVSO as of 2010
March 15.5 UT: P. Schmeer, Saarbruecken-Bischmisheim, Germany,
m(vis)=7.9 on 2010 March 12.184 (JD 2455267.684); B. Granslo,
Fjellhamar, Norway, m(vis)=8.5 on 2010 March 12.941 (2455268.441); B.
Granslo, m(vis)=8.8 on March 13.842 (2455269.342); B. Granslo,
m(vis)=8.6 on March 14.789 (2455270.289); K. Geary, Kingscourt, Ireland,
m(vis)=8.7 on March 14.8958 (2455270.3958); and V. Voropaev,
Krasnogorsk, Russia, m(vis)=9.2 on March 15.0129 (2455270.5129). 

V407 Cyg is located at the following (J2000) coordinates:

        RA: 21 02 09.85 , Dec: +45 46 33.0

Charts for V407 Cyg may be plotted at a range of scales using AAVSO VSP:

Please promptly submit all observations to the AAVSO using the name
"V407 CYG".

Congratulations to K. Nishiyama, F. Kabashima, T. Kojima, K. Sakaniwa,
and A. Tago for their discoveries!

This AAVSO Alert Notice was prepared by Dr. Matthew Templeton.


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