[vsnet-chat 3003] Re: SW Vul

[Taichi Kato <tkato>]

Re: [vsnet-chat 3001] SW Vul

   On SW Vul from previous VSNET postings:

(vsnet-obs 2800)

Dear Colleagues,

SW Vul, an UG object located at RA = 20h00m05.14s, Decl = +22d56'10.7"
(J2000.0) is undergoing a (very?) rare outburst !
The object (varying between mag 14.5p and 18.5p) is clearly visible on an
unfiltered CCD image, obtained at the CBA Belgium (using a 10" f/6.3 SCT and
ST-7 CCD) on May 19.066 UT. It is located VERY close to a 13.4 comparison
star (sequence T. Kato, Ouda Station, Japan) and therefore difficult to
estimate on the image. Its unfiltered mag is approx. 15.9.

Does anyone have additional information on this object ?

Kind regards,
Tonny Vanmunster
CBA Belgium

(vsnet-obs 2805)

   Though I don't have so much informtion on this object as I usually have
on other CVs, the object was discovered by Rosino in 1948.  Glasby (if I
remember correctly) gave an outburst cycle length of 13 days.  My earlier
inspection of the SW Vul field incidentally included in photographs of M27
also supported rather frequent outbursts.  Even though this material was not
statistically designed, the conclusion by Glasby seemed to me basically
correct.

Regards,
Taichi Kato

(vsnet-obs 2813)

Mr. Kato,                                                                       
You should ignore the report by Glasby, and all his writings.  Most of his
supposed observations were simply fictitious.  His work was repudiated many
years ago by the British Astronomical Association.  If you like, I can give
you references to the published announcements.

Best wishes -- John Isles.

(vsnet-obs 2815)

   Yes, his materials should be read with extreme caution, if not totally
ignored.  I wonder how he obtained such "fictitous" light curves like those
of UZ Boo and HT Cas.  In the SW Vul case, I think the result was derived
from other author's observation, and not his own  -- I should have treated
this reference as a secondary one.

   I have read in at least one reference SW Vul was treated as a possible
SU UMa star, but have totally forgotten where I read this.  This suggested
classification may have resulted from the short outburst cycle length,
which was originally supposed to be one of the chacteristics of SU UMa
stars.  Probably all these findings together with my result of photographic
inspection are consistent, but the inaccesibility to old materials has made
this "logical chase" quite incomplete.

Regards,
Taichi Kato

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