AG Dra brightening

[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 9283 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 9283 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

[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 9283 times

Comparison.png (4.33 KiB) Viewed 9243 times

[Francois Teyssier]

That's great, Umberto,

We can say when OVI vanished and when it reappers.

François

[Francois Teyssier]

Tonight spectrum
Clear night after several failures this week

_agdra_20160427_852_full_Raman OVI 6828_1.png (29.23 KiB) Viewed 9240 times

François

[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 9207 times

François

[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

[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 9149 times

[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

[Francois Teyssier]

Interesting, Tim !
You took it just during a second peak

AGDra.PNG (5.09 KiB) Viewed 9080 times

Unfortunatly, we have poor coverage of this second event.

François

[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 8996 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 8996 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