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Re: AG Dra brightening
Posted: Tue Apr 26, 2016 5:36 pm
by Francois Teyssier
Hello Paolo,
Your (very good) spectra are welcome in the data base ! Just send them by mail.
Update of AAVSO luminosity
- AGDra_AAVSO.PNG (6.2 KiB) Viewed 9293 times
Seems that the outburst is around its maximum luminosity (V ~ 9.25)
A got a low SNR spectrum the 25th (only 1 exposure between the clouds)
- _agdra_20160424_838_full_Raman OVI 6828_1.png (27.42 KiB) Viewed 9293 times
Raman OVI looks to recover (to be confirmed)
At date, no X-Rays from SWIFT observations (Steve's communication)
Of course, we go on !
Perhaps a window here tonight.
François
Re: AG Dra brightening
Posted: Tue Apr 26, 2016 5:39 pm
by umberto sollecchia
Salut, voici un nouveau profil de l'étoile observée 25-04-2016 et une comparaison entre le jour 19/04/2016 et 25/04/2016.Umberto
- Profilo Ag Dra.jpg (66.74 KiB) Viewed 9293 times
- Comparison.png (4.33 KiB) Viewed 9253 times
Re: AG Dra brightening
Posted: Tue Apr 26, 2016 7:54 pm
by Francois Teyssier
That's great, Umberto,
We can say when OVI vanished and when it reappers.
François
AG Dra : Raman OVI increases again
Posted: Wed Apr 27, 2016 9:27 pm
by Francois Teyssier
Tonight spectrum
Clear night after several failures this week
- _agdra_20160427_852_full_Raman OVI 6828_1.png (29.23 KiB) Viewed 9250 times
François
Re: AG Dra brightening
Posted: Fri Apr 29, 2016 4:06 pm
by Francois Teyssier
There's now (since 2016-04-17) a double absorption in the blue side of Balmer lines
Perhap's a shock in the red giant wind
- AGDra_Hb.PNG (13.08 KiB) Viewed 9217 times
François
Re: AG Dra brightening
Posted: Sat Apr 30, 2016 11:54 am
by Olivier GARDE
Some spectra taken last night with eshel spectrograph
The Raman O VI line is always present
Balmer lines with a little absorption visible in H Alpha and H Beta
And He II 4686
Re: AG Dra brightening
Posted: Thu May 05, 2016 11:54 am
by David Boyd
Last night AG Dra was at V = 9.21, 0.17 mag brighter than two nights previously, but the He II/H-beta line flux ratio continues to fall indicating a cooling of the WD.
David
- _agdra_20160504_870_D.Boyd_flux.png (26.47 KiB) Viewed 9159 times
Re: AG Dra brightening
Posted: Mon May 09, 2016 3:00 am
by Tim Lester
Here is AG Dra for May 6th at Hb and Ha.
Hb/HeII compared to fteyssier's result on May 1st. Shows the fairly rapid drop in ratio and line intensities.
Tim
Re: AG Dra brightening
Posted: Fri May 13, 2016 2:41 pm
by Francois Teyssier
Interesting, Tim !
You took it just during a second peak
- AGDra.PNG (5.09 KiB) Viewed 9090 times
Unfortunatly, we have poor coverage of this second event.
François
Re: AG Dra brightening
Posted: Sat May 28, 2016 3:15 pm
by Peter Somogyi
Hello,
After last weekend's clear night (= 3 day incl. Friday) + taking exceptionally this Thursday, let me summarize where I am with the +4 spectra within a week I've gathered, borrowing Tim Lester's and David Boyd's spectrum just from the edges of the critical observation hole (JD=2457515 - 2457521) when something important must have happened:
- graph_Ramans_20160526.png (17.34 KiB) Viewed 9006 times
Raman looks to be at peak compared to longterm with a raising trend, and last weekend it was still flickering. (Each had at least ~1.2 hour exposures so noise should be less than 0.05, based on my earlier per-exposure variations.)
- graph_AGDra_Multi_20160526.png (21.16 KiB) Viewed 9006 times
The reason chosing this unusual time window is to see whether things are settled or not. At least Balmer and HeI lines have jumped (compared to continuum) only within a week.
Hope you can continue, rainy season here.
Peter