IAU Circ., 9130, 1 (2010/March-0)
NISHIYAMA K., KABASHIMA F., KOJIMA T., SAKANIWA K., TAGO A., SCHMEER P. and MUNARI U.
Abstract (from CDS):
The Bureau received reports by Japanese amateurs (K. Nishiyama and F. Kabashima; T. Kojima; K. Sakaniwa; and A. Tago) of a possible new 7th-mag nova in Cygnus on wide-field camera-lens CCD images taken during Mar. 10.8-11.8 UT. Nishiyama and Kabashima suggested that this might be an unusually bright outburst of V407 Cyg (their astrometry yielding R.A. = 21h02m09s.83, Decl. = +45o46'33".0, equinox 2000.0) – not known to have been brighter than mag 13 since its 1936 discovery; it had been classified as a Mira variable with a symbiotic-star spectrum (e.g., Duerbeck 1987, Space Sci. Rev. 45, 1). Visual magnitude estimates by P. Schmeer, Bischmisheim, Germany: Mar. 12.184, 7.9; 17.183, 8.9; 18.191, 9.1. U. Munari et al. report (CBET 2204) that spectra from Mar. 13.09 show the absorption spectrum of the Mira star that is completely overwhelmed by the blue continuum from the outbursting component, a scenario reminiscent of the symbiotic recurrent nova RS Oph; the broad component of the Balmer emission series and He I lines looks closely similar to the spectrum of He/N classical novae. Additional details appear on CBETs 2199, 2205, and 2210.