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A spectrum obtained by Fran Cmapos shows the classical symbiotic AX Per in outburst
Large spectroscopic changes incomparison to recent spectra obtaines by Davis Boyd, Tony Rodda, James Foster, notably disappearence of [Fe VII] lines
(Cooling of the expended envelope)

ARAS DataBase: http://www.astrosurf.com/aras/Aras_Data ... /AXPer.htm

It is consistent with the rise of luminosity détected by David Boyd (V Band)
Further observations are strongly recommanded

François

Comments from Ausgustin Skopal


yes, that's right, AX Per is entering an outburst, although its
light curve from around 2007 seems to reflect a continuous active
phase. It is interesting that the forbidden line [FeVII] 6087 disappeared
on the October spectrum. If it is created by collisions at/around the
orbital plane between the stars, than it can be that something blocks
the fast particles from the hot component here. If this is a disk-like
structure around the WD, then a blue shifted absorption in hydrogen lines
should be (gradually) seen. Its connection with the hot component
is proved by its presence also around the orbital phase 0.5.
A significant broadening of the emission core/wings of, e.g., H-alpha
is observed during outbursts. Emissions of HeII and [OIII] are of
specific importance for understanding active phases of AX Per, etc.
Good luck, and all the best,

Augustin

Ooops!, What a surprise... I didn't noticed it. Apart from the dissapearance of the [FeVII] lines, I see a new broad band at 4637 A, maybe a triplet. Maybe NIII?

What I don't understand is why, in an outburst, the common enveloppe becomes colder. In this situation, I believed that the dissapearance of forbidden transitions is due to a increase of the density of the common enveloppe gas, so the evolution seems the opposite to the evolution of a nova towards the nebular phase... Well, I don't know... Surely I'm wrong

Kind regards!
Fran

These spectra show the change between Aug 31 and Oct 15 corresponding to a V magnitude increase from 11.33 to 10.87. The emission line flux of the hydrogen Balmer and He I lines has doubled. However both the He II and H-beta line fluxes have increased in the same proportion so the hot star temperature as estimated from the He II/H-beta ratio is almost unchanged. Also note that the [FeVII] emission line has disappeared (lower left plot).

David

A spectrum of AX Per taken the 20.9/10/2017 (RC 254 mm + eShel(2) + ASI1600MM):







Christian

Amazing spectrum Christian, the eShel(2) upgrade give a better response in the blue and go deep in the blue...

Bonsoir, le spectre d'AX FOR observé le 23-10-2017.Salut -Umberto

Here is my plot of AX Per from 2017-10-27.171.
I have also included the subplot centered on HeII at 4,885.68 for my last 5 observations.

cheers!
Woody

Details of AX Per spectrum taken the 7.8/11/2017 (RC 10 inch, modified eShel (135MM Samyang), ASI1600MM camera):





Christian

Prise de vue en deux parties de AX Per le 25/11/2017 avec le eShel modifié (l'objectif est à présent un Canon 135 mm f/2 L), une focalisation pour le visible, une autre pour l'UV, puis un aboutage des deux :









Christian