-------------------------------------------------------------------
THE ASTRONOMER Electronic Circular No 2629      2010 Mar 12 20.30UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074
INTERNET: GUY@TAHQ.DEMON.CO.UK      Backup: gmh@wdcc1.bnsc.rl.ac.uk
WORLD WIDE WEB                         http://www.theastronomer.org
-------------------------------------------------------------------
V407 CYGNI
Koichi Nishiyama, Japan has reported on CBET 2199 an apparent unusually 
bright outburst (mag 7.4) of the symbiotic star V407 Cyg on an 
unfiltered CCD image taken on 2010 Mar. 10.79 UT using a 105-mm camera 
lens + CCD. Nishiyama and Kabashima confirmed the outburst on two 
unfiltered CCD frames taken on Mar. 10.813 (at mag 6.8) and 10.814 (mag 
6.9) using a 0.40-m reflector + CCD; they also report the following 
pre-outburst magnitudes from unfiltered CCD images using the 105-mm 
lens: 2009 Sep. 3.66, 11.3; Oct. 3.54, 10.6; Nov. 3.46, 9.6; Dec. 3.42, 
9.2; 2010 Jan. 3.41, 9.2; 17.40, 9.3; Feb. 22.83, 9.6; Mar. 7.85, 9.8.

There is also an apparent independent discovery of this outburst by 
Tadashi Kojima, Japan, who reported it as a possible nova of mag about 7 
on two frames taken on Mar. 11.789 UT using a Canon EOS 40D Digital 
Camera (+ 50-mm f/2.8 camera lens mounted on a Sky-Memo equatorial 
instrument).  Nakano has measured the following position for the 
variable from Kojima's image, upon which the variable is at mag 7.3:
RA 21h 02m 10.18s DEC +45 46' 30.8" (2000; uncertainty about 8"). Kojima 
writes that nothing is visible at this position on his survey frames 
taken on 2010 Jan. 29 (limiting mag 11), Feb. 23, and 24 (limiting mag 
12).

The GCVS lists the position of V407 Cyg as

RA 21h 02m 09.9s DEC +45 46' 33" (2000), noting its observed range to be 
magnitude 13 to fainter than 17; it may have been a slow nova in 1936, 
and a Mira-type variable appears involved with this object, as well. 
Additional spectroscopy is urged to determine the nature of this object, 
as well as more accurate astrometry.

Editor adds:

According to Duerbeck's 'A Reference Catalogue and Atlas of Galactic 
Novae' the object was discovered by C. Hoffmeister on Sonneberg plates 
and initially classified as a nova-like object but later as ZAND. A 
major outburst occurred in 1936 (VSS 1 [1949] 295) when the star rose on 
1936 August 29 and then followed a steady decline but was traceable 
until 1939 August. L Meinunger finds Mira-type variability (MVS 3 [1966] 
111).

On AAVSO special notice 201:
Charts for V407 Cyg may be plotted using AAVSO VSP:

http://www.aavso.org/observing/charts/vsp/index.html?pickname=V407%20Cyg

They note that the sequence has been updated to include more appropriate 
stars for its current magnitude range.

Guy M Hurst