[vsnet-alert 9394] V337 Cyg outburst and fading

[Taichi Kato]

   V337 Cyg (SU UMa-type) outburst, followed by a rapid fading.
The last superoutburst was in 2006 May (next one may be due).
The current fading may represent a precursor outburst to a
superoutburst.

  20070701.969  15.80V  (Tomas L. Gomez)
  20070702.937  16.73V  (Tomas L. Gomez)

   From BAA VSS alert:

===

The ROP star V337 Cyg has been reported to be in outburst
by T. Gomez (see below).

This would be the first recorded outburst since November
2006 (normal outburst 16.4C).  The magnitude level mentioned
by Gomez below is approaching that of the May 2006 superoutburst
(15.2), which was the first to be identified.
See http://arxiv.org/abs/astro-ph/0702607 for more info.

Close monitoring is requested, as is time series if at all
possible.

===

  From vsnet-alert 7802 (2003), info compiled by P. Schmeer:

Although Jan Manek determined a mean cycle length of 32 days
no outbursts of this dwarf nova have been reported to VSNet
since his detection of the 1997 Aug. 20 outburst (see below). 
 
Regards,
Patrick
 
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   * Date: Thu, 12 Sep 1996 10:09:30 +0200
   * To: vsnet at kusastro.kyoto-u.ac.jp
   * From: Jan Manek <jmanek at mbox.vol.cz>
   * Subject: [vsnet 782] V337 Cyg

Hi all,

once more regarding V337 Cyg.

I have just finished measuring of the scan of outburst plate and get
following position using 10 GSC stars:

    19 59 52.88  +39 13 59.0  (2000.0)

with uncertainity + - 0.4" in both coordinates. This is in excellent
agreement with Bruce Sumner's position of the candidate he measured
on DSS.

Below you can also find JD dates of outbursts I found (not checked all
possible plates in Sonneberg plate archive). Individual outbursts are
separated by blank line. There were 6 outbursts (not only 3 as I mentioned
earlier) recorded. There seems to be recurrence period about 30 days.

   2446977.481

     47263.575

     47329.488
          .500
     47331.473
          .489

     47365.461
     47368.509

     47391.480

     47592.669

Regards, Jan

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  Date: Thu, 21 Aug 1997 09:28:18 +0200 
  To: vsnet-alert at kusastro.kyoto-u.ac.jp 
  From: Jan Manek <jmanek at mbox.vol.cz> 
  Subject: [vsnet-alert 1146] Outburst of V337 Cyg 
  Cc: vsnet-obs at kusastro.kyoto-u.ac.jp 

Observation by Jan Manek (MEK)

V337 Cyg   Aug 20.9516   15.60    outburst (no doubt)

65cm reflector+CCD+V filter

I would like to point out that this is the first live event observed
for this star. Follow up observations are needed. I mentioned 
in [vsnet 782] that periodicity is 30 days but more probably it 
is around 32 days.

I have also remeasured position of this star on two of this night CCD
frames and position using 10 stars from GSC 1.2 is following:
    19h 59m 52.96s   +39o 13' 59.8"     (2000.0)
           +-0.01            +-0.1

Regards, Jan

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   * Date: Fri, 22 Aug 1997 22:45:11 +0200 (MET DST)
   * To: tvanmuns at innet.be
   * From: Tonny Vanmunster <tvanmuns at innet.be>
   * Subject: [vsnet-alert 1152] CVC 146 (V337 Cyg)

BELGIAN ASTRONOMICAL SOCIETY V.V.S. -  Working Group Variable Stars
Cataclysmic Variables Circular No.146               1997, August 22
Ed.: T. Vanmunster, Walhostraat 1A, 3401 Landen, BELGIUM
     Internet: tvanmuns at innet.be                  TEL. 32-11-831504
     CVC Web Page : http://www.astro.columbia.edu/~cba/cvc
===================================================================

V337 Cyg [UG:, 14.4p - <16.5p]
==============================

Jan Manek, Stefanik Observatory, Czech Republic, reports his detection
by CCD of an outburst of this very interesting dwarf nova, which is
part of the Belgian Cataclysmic Variables Alert Programme (CVAP).
Lasse Jensen, CBA Denmark has been able to confirm the outburst.
The available observations are as follows :

1997 Aug 15.966 UT, <14.4   (G. Poyner, 0.40-m refl., visual);
     Aug 19.873 UT, <16.3   (T. Vanmunster, 0.25-m refl., unfilt CCD);
     Aug 20.951 UT,  15.60V (J. Manek, 0.65-m refl., CCD+V);
     Aug 21.849 UT,  15.7   (L. Jensen, 0.25-m refl., unfilt CCD);

V337 Cyg was discovered by Walter Baade in 1928 (Astron. Nach. 232,
65). Jan Manek apparently already studied V337 Cygni's outburst
behaviour in quite some detail back in 1996. In a September 1996
VSNET message he wrote, as a result of a screening he did of plates
in the Sonneberg plate archive : "I have found V337 Cyg in at least 3
outbursts, being usually less than 5 days long and reaching about mag
15 in maximum on blue plates. In minimum it is below the plate limit
(< 18 mag pg). Plate scans were made for both (maximum and minimum)
states." Manek later announced 3 more outbursts on archive plates and
noticed a recurrence period of about 32 days.

Accurate astrometry by Manek reveals following coordinates (J2000.0) :
R.A. = 19h59m52.96s, Decl.= +39d13'59.8".

Since previous outbursts of V337 Cyg have not been studied in detail,
it is of extreme importance to monitor the present outburst as
intensively as possible.

Tonny Vanmunster
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