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V Sge

Posted: Thu Jul 14, 2016 11:51 pm
by Francois Teyssier
An attempt on this enigmatic star with eShel at R = 11000
V mag ~ 11.5

VSge.PNG
VSge.PNG (17.66 KiB) Viewed 11382 times
François

Re: V Sge

Posted: Sat Jul 23, 2016 3:30 pm
by Peter Somogyi
V Sge from last night, with my new 300/1200 Newton:
vsge_20160722_red.jpg
vsge_20160722_red.jpg (34.75 KiB) Viewed 11328 times
vsge_20160722_blue.jpg
vsge_20160722_blue.jpg (46.57 KiB) Viewed 11328 times
HeII 4686 / H-beta ratio jumped to 2:1, as I see. Inserting to my daily list...

Happy hunting!
Peter

Re: V Sge

Posted: Sat Jul 23, 2016 5:09 pm
by Francois Teyssier
That's great !
Very impressive changes in only a few days
R = 2500 is suffisent to get the profile
A (almost) daily coverage should be great this summer
François

Re: V Sge

Posted: Sun Jul 24, 2016 11:02 am
by Peter Somogyi
Change since previous night, approx. 1 hour (6 * 600 sec) exposures each:
vsge_20160722vs23_Ha.png
vsge_20160722vs23_Ha.png (22.57 KiB) Viewed 11295 times
Had to fix a 'wavelength registration' error manually from yesterday (estimated skews were nonlinear and first far from zero), fortunately made a safety last calibration frame and interpolated the shift by producing weighted average calibration frames. (Approx. 1.5 A skew introduced.)

Another local effect could be, that this time unusual gaps appeared left to H-alpha (local fog?) visible on both 29-Vul and 1-Sge (= safety ref.star, to confirm 29-Vul) taken at the same time, it should be wise to do a telluric calibration around H-alpha to see the full truth. (Can send the ref.stars upon request, or I can try it later...)

Blue part looks free of errors:
vsge_20160722vs23Hb.png
vsge_20160722vs23Hb.png (20.77 KiB) Viewed 11295 times
Further increase at HeII 4686 blue wing.

Peter

Re: V Sge

Posted: Mon Jul 25, 2016 3:21 am
by Tim Lester
A very long exposure of 8 x 1200 sec at R = 6400.
S/N not as good as I had hoped for.
vsge_ 20160724_106_tlester.png
Tim

Re: V Sge

Posted: Mon Jul 25, 2016 2:42 pm
by Francisco Campos
Hello,

I move this post here in order to merge all the spectra.

Yesterday I took a new spectrum and has changed considerably from the very early days of July. Even at low resolution the changes are very clear.

Another curious feature is that continuum increases at low wavelenghts.

Meanwhile, the big question is... what's going on in V Sge? It is maybe a microquasar like V694 Mon or SS433? I have never seen a spectrum like this... :?:

Greetings
Fran
_vsge_20160723_985.png
_vsge_20160723_985.png (9.3 KiB) Viewed 11255 times
V Sge .png
V Sge .png (11.57 KiB) Viewed 11255 times

Re: V Sge

Posted: Mon Jul 25, 2016 6:20 pm
by Francois Teyssier
All that is excellent and very exciting
I opened a page in the base : http://www.astrosurf.com/aras/Aras_Data ... e/Vsge.htm
Waiting for your (good spectra)

V Sge ( and from it V Sge stars) is an enigmatic star, with a period of ~ 0.5 day and strong eclipses
I'll write a resume from publications

François

Re: V Sge

Posted: Mon Jul 25, 2016 7:05 pm
by Peter Somogyi
Yesterday could catch only 2 x 900 sec usable exposures (out of the many...), and just for the blue region:
vsge_20160724_vs_0723_vs_0722.png
Above 2 charts comparing yesterdays result to the previous days, showing the full weekend serie.
Suggests the wings might change suddenly.

The most useful description I saw is opening from vsx:
https://www.aavso.org/vsx/index.php?vie ... &oid=27346
See the doc from 1965, however I was unable to access the real content from 1983.

Peter

Re: V Sge

Posted: Mon Jul 25, 2016 9:29 pm
by etienne bertrand
Spectre très intéressant. Les raies en émission sont larges et très nombreuses ; serait-il possible d'avoir des informations qui expliquent le spectre ?
Merci pour ce bon travail.

Re: V Sge

Posted: Wed Jul 27, 2016 9:41 pm
by Tim Lester
Halpha for July 27 at R = 9000. (H2O removed)
vsge_ 20160727_135_Ha_tlester.png
vsge_ 20160727_135_Ha_tlester.png (22.54 KiB) Viewed 11187 times
Tim