Possible brightening og V1363 Cyg

(vsnet-obs 3765)

Dear colleagues,

The possible outburst/brightening of V1363 Cyg, reported by Gary Poyner, has been confirmed by CCD at the CBA Belgium (25-cm f/6.3 SCT and ST-7 CCD). The CCD images were obtained under very poor conditions (strong winds, clouds), but clearly show the presence of a faint object. A rough analysis of an unfiltered CCD image, obtained at 23h19m UT (Sep 12, 1996) yields a magnitude of 16.5 (using the 15.60 comp. star on the TA sequence).

V1363 Cyg is not visible on earlier CCD images, obtained at the CBA Belgium, although they have a similar limiting magnitude. This further proves the reality of the object.

The Outburst Activity Database on Selected Cataclysmic Variables contains no entries on past outbursts of this object.

Kind regards,
Tonny Vanmunster,
CBA Belgium

Historical behavior

(vsnet-obs 3769)

V1363 Cyg (=VV 279)

Tonny Vanmunster wrote in vsnet-obs #3765:

> V1363 Cyg is not visible on earlier CCD images, obtained at the CBA Belgium, 
> although they have a similar limiting magnitude. This further proves the
> reality of the object.
>
> The Outburst Activity Database on Selected Cataclysmic Variables contains no
> entries on past outbursts of this object.

According to the discovery paper (Ric. Astr. Vol. 8, No. 10), V1363 Cyg showed very peculiar behavior unlike other dwarf novae.

       JD       magnitude
     (+2400000)
 ----------------------------------------------------------------------
  around 32400: fainter than 17.5
  around 32600: observed at 13-14 for about 40 days
                then faded again to 16-<17.5
         32950: started to brighten slowly
         33000-33200: 14-15 mag
                then slowly faded to mag 17 around 33600
         33980: started to brighten, reaching a maxium of 13.5 around
                34000
         34100: 15-16 mag
         34150: 13.5, then faded to
  around 34200: 14-14.5
         34220: faded further to mag 16
         34230: brightened again to mag 14
                then faded very slowly to mag 18 around 35000

From the time-scale of variations, the object looks like an anti-dwarf nova (like MV Lyr and KR Aur) rather than usual Z Cam stars. Spectroscopic observation by Bruch and Schimpke 1992 (A&AS 93, 419) confirmed its cataclysmic nature. Recent faint state of this object is remniscent of the "superminimum" of MV Lyr. The ROSAT Bright Source J2006.2+2342 may be identified with this CV. Close follow-up observations are urged to see if the star may become active again.

Regards,
Taichi Kato

CCD image and chart

Recent light curve

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