[vsnet-alert 12032] Re: WX SGR

[Wolfgang Renz]

Hi Rob

> About 2 hours ago, I imaged a wide field that included the eclipsing binary
> WX SGR.   I haven't been able to image this field since 2 June, but the
> magnitude tonight was considerably lower than it normally is.  I have no
> idea how this star behaves or whether this is a notable event or not.
> http://i727.photobucket.com/albums/ww271/Rob_Kau/WXSGRanimation.gif


Did you check if it was in an eclipse during you imaged it ?


WX SGR:
http://simbad.u-strasbg.fr/simbad/sim-id?Ident=V*+WX+Sgr&submit=display+selected+measurements
http://www.sai.msu.su/gcvs/cgi-bin/search.cgi?search=WX+Sgr
http://www.aavso.org/vsx/index.php?view=detail.top&oid=27746
is a well observed:
http://var.astro.cz/ocgate/ocgate.php?star=WX+Sgr&submit=Submit&lang=en
EA/SD eclipsing binary:
http://cdsarc.u-strasbg.fr/viz-bin/vizExec/w/getype?-plus=-+&B/gcvs&EA/SD
with a range 9.6-11.3(9.9) mag p. As the brighter component has
a listed spectral types of A1 and A0, the max mag should be about
the same in all pass band.

Kreiner obviously thinks that the fainter component of the for us un-
resolvable double is the variable (by giving the max mag to be 12.5
mag V) which cann't be as the amplitude of 1.7 mag p and 1.8 mag
V is too large to cause such a mag drop in an unresolved double
with a ~ 9.44 mag V brighter component:
http://www.as.ap.krakow.pl/o-c/data/getdata.php3?WX%20Sgr

The TYC LC doesn't help much as it doesn't show fainter-thans:
http://cdsarc.u-strasbg.fr/viz-bin/vizExec/Vgraph?cat=I%2F239&-graph=6254-172-1%09&P=2.12927&-graph=-Y%09mag&-x0=&-x1=&--bitmap=600x600&-y0=-&-y1=-&-y2=-
But ASAS shows a nice EA/SD LC varying 9.38-11.05(9.48) mag V:
http://www.astrouw.edu.pl/cgi-asas/asas_variable/175924-1723.9,asas3,2.12927,-4481.4580,800,600,0

The most up to date Kreiner elements can be found here:
http://www.as.wsp.krakow.pl/minicalc/SGRWX.HTM
It says that the last primary minimum was at::
2010-06-12 09:07:10.27 UTC = HJD 2455359.87998
So it looks like as you caught it accidentially at or pretty close to
its minimum light.

Clear skies
 Wolfgang

-- 
Wolfgang Renz, Karlsruhe, Germany