AX Per Stong outburst

AX Per Stong outburst

Postby Francois Teyssier » Fri Apr 12, 2019 2:59 am

The recent spectra in the database (D. Boyd, W. Sims, C. Boussin, F. Campos) and photometry obtained by David Boyd show that the prototypical symbiotic star AX Per is in strong outburst (V = 10.3)

V mag according to phase (P = 680 days)
Current cycle (brown squares) strongly different from former ones
AXPer.PNG
AXPer.PNG (16.92 KiB) Viewed 1507 times


Classical symbiotic outburst (expansion and cooling of the accreting layer on the white dwarf)
High ionized lines (notably [Fe VII] disapear
axper_20190410_846_D.Boyd.png


Spectra of the event are very welcome
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Re: AX Per Stong outburst

Postby Christophe Boussin » Fri Apr 12, 2019 11:31 pm

Hello Francois,

I obtained the following spectrum the 11th of April at 20 h 49 TU with a resolution of 507 (JJ = 2458585.3675) and an acquisition time of 30 min :


_axper_20190411_867_Christophe Boussin_3700_7570.png
AX Per on April 11th, 2019
_axper_20190411_867_Christophe Boussin_3700_7570.png (77.92 KiB) Viewed 1479 times


As an indication, identification of some lines :

AX PER_20190411_867_Christophe Boussin.png
AX Per on April 11th, 2019 (identification from PlotSpectra)


The comparison of my spectra between 17 February and 11 April that shows the disappearance of the [FeVII] line at 6087A :

Fe[VII]6087_axper_Christophe Boussin.png
[FeVII] line at 6087A
Fe[VII]6087_axper_Christophe Boussin.png (29.04 KiB) Viewed 1479 times


At the same time, for example, the relative intensities of the Halpha line and the HeI line at 6678A increase :

Halpha_axper_Christophe Boussin.png
Halpha
Halpha_axper_Christophe Boussin.png (27.26 KiB) Viewed 1479 times


HeI6678_axper_Christophe Boussin.png
HeI line at 6678A
HeI6678_axper_Christophe Boussin.png (26.81 KiB) Viewed 1479 times



Clear skies,

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan) @ ARAS database
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Re: AX Per Stong outburst

Postby Francois Teyssier » Sat Apr 13, 2019 12:03 pm

That's excellent
The ATel, writtren by Jaroslav and Rudolf,

http://www.astronomerstelegram.org/?read=12660

The symbiotic star AX Per is going into strong outburst
ATel #12660; J. Merc (UPJS in Kosice, Charles University), R. Galis (UPJS in Kosice), F. Teyssier, D. Boyd, W. Sims, C. Boussin, F. Campos (ARAS)
on 13 Apr 2019; 11:21 UT
Credential Certification: Jaroslav Merc (jaroslav.merc@student.upjs.sk)
Subjects: Optical, Request for Observations, Cataclysmic Variable, Transient, Variables

AX Per is a well-known eclipsing symbiotic binary consisting of a giant of type M4.5 III (Muerset & Schmid 1999, A&AS, 137, 473) and probably a white dwarf. The orbital period of the binary system is around 680 days (Mikolajewska & Kenyon 1992, AJ, 103, 579). The light curve of AX Per is characterized by the wave-like variations whose shape is changing from cycle to cycle. After major outbursts of the system in 1988-1992, a new activity stage has begun in 2007, with minor outbursts observed in 2009, 2010, 2012 and 2014 (Munari & Siviero 2009, CBET, No. 1757; Munari , Siviero, et al. 2010, CBET, No. 2555; ATel #4265, ATel #6382). All recent outbursts were significantly lower in magnitude (maximal V around 10) than the major outbursts in 90s (with V < 9). In this Astronomer's Telegram, we report the beginning of a new outburst of AX Per with a strong increase in brightness. In the previous orbital cycle, the brightness of the symbiotic system reached the maximum of B=11.589 and V=10.873 (October 15, 2017; JD 2458042.319). During the binary eclipse in August/September 2018, the magnitudes decreased to the minimum of B=13.387 and V=12.355 on August 21, 2018 (JD 2458352.375). Since then, the brightness of AX Per has started to increase and the March 2019 measurements have shown that it has reached a similar level or was higher than the previous maximum of B=11.516 and V=10.652 (March 24, 2019; JD 2458567.330). Our observation obtained on April 10, 2019 (JD 2458584.337) indicate that the AX Per brightness continues to rise (B=11.109 and V=10.330) in what looks like a promising major outburst of this symbiotic binary. The low resolution spectroscopic observations (R < 1000) obtained during March and April 2019 showed significant changes in the prominent emission lines and in the continuum compared to the spectra acquired at the end of 2018. We note the disappearance of the highly ionized lines (e. g. [Fe VII]) or the change of the He I singlet/triplet ratio. Several emission lines of the He I which were not observable are fairly strong in the recent spectra, and similar behavior is observed in the case of Fe II lines. The Balmer lines equivalent widths have also increased significantly (1.3 times since December 2018). Nebular-to-auroral line ratio of [OIII] 5007/4363 has increased from 0.7 to 1.6. This behavior points to a classical symbiotic outburst during which a accreting layer on white dwarf expands and cools down. We will continue the photometric and spectroscopic monitoring of the AX Per current outburst. It will be interesting to see if the outburst is another of a series of minor outbursts, or we will finally observe a major outburst of this symbiotic system. Recent spectroscopic observations could be found in the ARAS Spectral Database (link to the database below).
ARAS Spectral Database
Francois Teyssier
 
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Re: AX Per Stong outburst

Postby Christophe Boussin » Sat Apr 13, 2019 2:07 pm

Thank you François, it's a very good news !!
This is a great acknowledgment of our constant efforts and a serious encouragement to monitor AX PER even more !
Once again, thank you for the work you do !

Spectroscopically,

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan) @ ARAS database
Christophe Boussin
 
Posts: 57
Joined: Sun Aug 21, 2016 6:04 pm

Re: AX Per Stong outburst

Postby Christophe Boussin » Mon Apr 22, 2019 8:56 pm

Hello all,

Here is my last contribution to the monitoring of AX Per outburst.
I obtained the following spectrum the 20th of April at 20 h 58 TU with my Alpy 600 (resolution of 505, JJ = 2458594.3738) and an acquisition time of 30 min :

_axper_20190420_874_Christophe Boussin_3700_7570.png
AX Per on April 20th, 2019
_axper_20190420_874_Christophe Boussin_3700_7570.png (80.16 KiB) Viewed 1391 times


As an indication, identification of some lines :

AX PER_20190420_874_Christophe Boussin.png
AX Per on April 20th, 2019 (identification from PlotSpectra)


As in the spectrum of April 11, the absence of the [FeVII] line at 6087A is noticeable :

Fe[VII]6087_axper__Christophe Boussin.png
Fe[VII] line at 6087A
Fe[VII]6087_axper__Christophe Boussin.png (32.88 KiB) Viewed 1391 times


Since April 11, for example, the relative intensities of the Halpha line and the HeI line at 6678 remain, approximately, unchanged :

Halpha_axper_Christophe Boussin.png
Halpha
Halpha_axper_Christophe Boussin.png (31.54 KiB) Viewed 1391 times


HeI6678_axper_Christophe Boussin.png
HeI line at 6678A
HeI6678_axper_Christophe Boussin.png (31.36 KiB) Viewed 1391 times



Clear skies,

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan) @ ARAS database
Christophe Boussin
 
Posts: 57
Joined: Sun Aug 21, 2016 6:04 pm

Re: AX Per Stong outburst

Postby Christophe Boussin » Mon Apr 29, 2019 4:45 pm

Hello all,

After a cloudy day, I was lucky to see the sky clear again in the early evening on April 24th !
The weather has improved long enough to allow me to get another spectrum of AX Per with a perfectly clear sky...before the clouds came back !

So, I obtained the following spectrum the 24th of April at 20 h 29 TU with my Alpy 600 (resolution of 504, JJ = 2458598.3541) and an acquisition time of 20 min :

_axper_20190424_854_Christophe Boussin_3700_7570.png
AX Per on April 24th, 2019
_axper_20190424_854_Christophe Boussin_3700_7570.png (80.01 KiB) Viewed 1329 times


As an indication, identification of some lines :

AX PER_20190424_854_Christophe Boussin.png
AX Per on April 24th, 2019 (identification from PlotSpectra)


Clear skies,

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan) @ ARAS database
Christophe Boussin
 
Posts: 57
Joined: Sun Aug 21, 2016 6:04 pm

Re: AX Per Stong outburst

Postby Christophe Boussin » Sun May 12, 2019 3:21 pm

Hello all,

AX Per is now too low in the evening sky so I can't get any spectrum anymore because of the vegetation that surrounds me... but, it remains the morning sky !

The spectrum below, obtained this morning (12th of May at 01 h 19 TU, resolution 501, JJ = 2458615.5551) with my Alpy 600, is the result of 5 exposures of 300 s each :

_axper_20190512_055_Christophe Boussin_3700_7570.png
AX Per on May 12th, 2019
_axper_20190512_055_Christophe Boussin_3700_7570.png (77.07 KiB) Viewed 1236 times


As an indication, identification of some lines :

AX PER_20190512_055_Christophe Boussin.png
AX Per on May 12th, 2019 (identification from PlotSpectra)


The relative intensity of the Halpha line is still increasing...

Halpha_axper_Christophe Boussin.png
Halpha
Halpha_axper_Christophe Boussin.png (35.25 KiB) Viewed 1236 times


...but that of the HeI line at 6678A, for example, seems to be decreasing :

HeI6678_Christophe Boussin.png
HeI line at 6678A
HeI6678_Christophe Boussin.png (35.11 KiB) Viewed 1236 times


Does anyone else notice a similar evolution?

Clear skies,

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan) @ ARAS database
Christophe Boussin
 
Posts: 57
Joined: Sun Aug 21, 2016 6:04 pm

Re: AX Per Stong outburst

Postby Francois Teyssier » Sun May 12, 2019 4:25 pm

C'est déjà très bien d'avoir pu la suivre jusque là, Christophe.
D'après la courbe AAVSO, le pic a été atteint vers le avril, à mag V ~ 10.2.
Tu as aussi le blend CIII/NIII 4640-4660 qui caractérise bien l'outburst (avec la disparition de [Fe VII]
François
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Re: AX Per Stong outburst

Postby Christophe Boussin » Sat Jun 01, 2019 9:03 pm

Hello all,

Thank you François !
AX Per is now more easily visible in the morning sky, so I was able to resume the monitoring...
The spectrum below, obtained this morning (June 1st at 01 h 10 TU, resolution 500, JJ = 2458635.5489) with my Alpy 600, is the result of 9 exposures of 300 s each :

_axper_20190601_049_Christophe Boussin_3700_7570.png
AX Per on June 1st, 2019
_axper_20190601_049_Christophe Boussin_3700_7570.png (74.97 KiB) Viewed 1061 times

Comparison of the spectra of May 12th and June 1st :

AXPER_Christophe Boussin.png
AX Per on May 12th and June 1st, 2019 (identification of some lines from PlotSpectra)


AXPER_zoom_Christophe Boussin.png
AX Per on May 12th and June 1st, 2019 (zoom)

We can note the decrease of the relative intensities of the spectral lines (like those of the CIII/NIII blend and the HeII line at 4686A) :

CIIINIII_axper_Christophe Boussin.png
AX Per on May 12th and June 1st, 2019 (NIII/CIII blend and HeII line at 4686A)
CIIINIII_axper_Christophe Boussin.png (26.59 KiB) Viewed 1061 times

Clear skies,

Christophe BOUSSIN
CBO (Newton 200 F/5 / Alpy600 / Atik 314L+ / Atik Titan) @ ARAS database
Christophe Boussin
 
Posts: 57
Joined: Sun Aug 21, 2016 6:04 pm

Re: AX Per Stong outburst

Postby Francois Teyssier » Sun Jun 02, 2019 3:16 pm

C'est excellent, Christophe
Cela fait un trou de 2 semaines seulement dans le suivi.
A poursuivre tout au long du déclin, pour voir réapparaître [Fe VII]

François
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