Call for monitoring of AG Dra by R. Galis & al.

Call for monitoring of AG Dra by R. Galis & al.

Postby Francois Teyssier » Wed Mar 29, 2017 9:19 am

Dear all,

A Professional team call us for a monitoring of AG Dra
(See above)

Cadency : ~ one Spectrum a week at various resolution (from low to high)
Of course, especially for low resolution spectra try to get the better response as possible
and flux calibrated spectra + BVR photometry should be a must
Echelle spectra at the same xadency are requested

A usual, send spectra to francoismathieu.teyssier bbox.fr
and we keep the touch throw the forum

Of course, I'm very happy to see that our team as an excellenrt visibility amoung the professionnal symbiotics community
thanks to all your observations
That's great!


François

The pdf will be on line this afternoon


Call for observation of the outburst activity of symbiotic binary AG Draconis
Rudolf Gális1, Jaroslav Merc1 & Laurits Leedjärv2

(1) Department of Theoretical Physics and Astrophysics, Institute of Physics, Faculty of Science, P. J. Šafárik University, Park Angelinum 9, 040 01 Košice, Slovakia, rudolf.galis@upjs.sk
(2) Tartu Observatory, Observatooriumi 1, Tõravere, 61602 Tartumaa, Estonia

AG Dra is one of the best studied symbiotic systems, thanks to its relatively high brightness and high Galactic latitude favorable for observations. The system undergoes characteristic symbiotic activity with alternating quiescent and active stages. During quiescence, the mean magnitude of AG Dra is 11.4, 11.1 and 9.8 mag in U, B and V filter, respectively. The amplitude of the brightness variations decreasing with wavelength, from 1.3 mag in the filter U to 0.4 mag in the filter V. The active stages consist of several outbursts of about 1–1.4 mag in the V/visual band and up to 2.3 and 3.6 mag in the B and U bands, respectively. Major outbursts occur in intervals of 12–15 yr (in 1936, 1951, 1966, 1980, 1994 and 2006), and are usually followed by minor-scale outbursts in intervals of about 1 yr (Hric et al. 2014). Using UV and X-ray observations, González-Riestra et al. (1999) showed that there are two types of outbursts: cool and hot ones. In our recent paper (Leedjärv et al. 2016) we demonstrated that the outbursts of AG Dra can be clearly distinguished also according to behavior of the prominent emission lines in optical spectra.
After seven years of flat quiescence following the 2006-08 major outbursts, in the late spring of 2015, AG Dra begun rising again in brightness toward what appeared to be a new minor outburst (Fig. 1). The recent outburst activity of AG Dra was definitely confirmed by a more prominent outburst in April 2016. The photometric observations suggest that these outbursts are of the hot type. Such behaviour is quite unusual, because the major outbursts in the beginning of active stages are usually cool. Moreover, the spectroscopic observations suggest that the minor outburst of AG Dra in April 2016 demonstrates the behaviour of both hot and cool outbursts. Is it a new type of outburst or some kind of transition between (or combination of) the hot and cool outbursts?

AGDra.PNG
AGDra.PNG (54.9 KiB) Viewed 4327 times

Figure 1: UBV LCs from the period 1963–2016 with marked active stages (C, D, E + F and G) and quiescent ones (Q4, Q5 and Q6). Particular outbursts are assigned as C1, C2, D1 – D5, E0 – E10, F1, F2 and G0, G1. The thin curves show spline fits to the data points.
Another interesting question is the next evolution of activity of the symbiotic binary AG Dra. According to our detailed period analysis of photometric and spectroscopic observations we know that the median of the time interval between outbursts is around 365 days. It is worth noting that these time intervals vary from 300–400 d without an apparent long-term trend. Nevertheless, can we expect the major cool or minor hot outburst during the late spring of 2017? Or maybe none of them and AG Dra will return to quiescence as we have already detected such behavior during the weak activity stage 1963–66. In any case, AG Dra clearly demonstrates the importance of long-term monitoring of symbiotic stars in order to disentangle the nature and mechanisms of their active stages and outbursts.
According the aforementioned, we kindly ask the ARAS observers for spectroscopic monitoring of AG Dra in the coming period. The spectroscopic observations with a cadence of 5-10 days will be sufficient to monitor AG Dra during ongoing quiescent stage. Daily monitoring is highly desirable during next potential outbursts, which will be announced by the special alert based on photometric observations of this interesting symbiotic binary.
Thank you very much in advance.
References:
González-Riestra R., Viotti R., Iijima T., Greiner J., 1999, A&A 347, 478
Hric, L., Gális, R., Leedjärv, L., Burmeister, M., Kundra, E., 2014, MNRAS 443, 1103
Leedjärv, L., Gális, R., Hric, L., Merc, J., Burmeister, M., 2016, MNRAS 456, 2558
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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby Francois Teyssier » Wed Mar 29, 2017 4:39 pm

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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby Olivier GARDE » Thu Mar 30, 2017 12:24 pm

Here's a spectrum taken last night with an eShel spectrograph and more than 3 hours total exposure to improve SNR in the blue part of the spectrum.

The full spectrum (23 orders merged)

Image

and the Balmer lines profils.

Image
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby Peter Somogyi » Thu Mar 30, 2017 8:50 pm

I think it's worth noting here that my last weekend's result tell both Raman OIV lines jumping out:

RamanOIV_6826.png
RamanOIV_6826.png (52.42 KiB) Viewed 4255 times

RamanOIV_7088.png
RamanOIV_7088.png (53.12 KiB) Viewed 4255 times


Whilst H-alpha decreased a lot:
Halpha.png
Halpha.png (25.92 KiB) Viewed 4255 times


Although haven't used this resolution since end of last year.
All R~2500 except the last that was R~3300.

BTW I'd recommend doublechecking the SNR requirement on Raman OIV 7088 - my last information that EW of the 6826 and 7088 is necessary for some caltulations, this probably means an unexpectedly longer exposure time and some separation from the HeI 7065.

Happy hunting!
Peter

EDIT: using PlotSpectra here, thanks for Tim Lester to make it!
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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby umberto sollecchia » Fri Mar 31, 2017 10:08 am

Bonjour, voici ma contribution.
Umberto

Profilo AG Dra.jpg
Profilo AG Dra.jpg (82.78 KiB) Viewed 4178 times
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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby Paolo Berardi » Sun Apr 02, 2017 6:41 pm

Hi all, my observation for 31 march. Lhires III 2400 (R ~16000).

Image

Paolo
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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby Joan Guarro Flo » Mon Apr 03, 2017 6:47 pm

Hi,

Is AG Dra, in the night 2017 04 01/02.

Cheers, Joan.
Attachments
_agdra_20170402_044_J. Guarro.png
_agdra_20170402_044_J. Guarro.png (6.25 KiB) Viewed 4145 times
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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby Francois Teyssier » Thu Apr 06, 2017 8:53 pm

The request for photometry campaign is published on AAVSO site
https://www.aavso.org/aavso-alert-notice-572

Alert Notice 572: AG Dra monitoring requested

April 3, 2017: Dr. Rudolf Gális (Pavel Jozef Šafárik University (Slovakia)) and colleagues have requested AAVSO assistance in observing the symbiotic variable AG Dra. Observations are requested as a follow-up to spectroscopic observations and in order to monitor the system for an anticipated outburst.

Dr. Gális writes: "AG Dra is one of the best studied symbiotic systems, which undergoes characteristic symbiotic activity with alternating quiescent and active stages. The latter ones consist of several outbursts in intervals of about 1 yr. After seven years of flat quiescence following the 2006-08 major outbursts, in the spring of 2015, AG Dra...[entered the active stage]...with...two minor outbursts (in 2015 and 2016) up to now. Such behaviour is quite unusual in the photometric history of AG Dra, so the further systematic photometric monitoring of this symbiotic binary is highly desirable. We expect the next outburst of AG Dra in the late spring of 2017..."

Daily monitoring of AG Dra (V~7.9-10.3) in UBV(RI) filters is requested beginning at once and continuing until further notice. Visual observations are welcome and are encouraged. When the outburst occurs, revised observing instructions will likely be issued via an AAVSO Special Notice. Observers are urged to subscribe both to Alert Notices and Special Notices so as to be kept informed.
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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby Francois Teyssier » Tue Apr 11, 2017 3:54 am

At the date, the mon itoring is (very!) compliant to what is expected.

More precise specifications:

The resolution should at least 1800
The main insterest zone is 6700-7200 (Raman OVI). The second Raman line 7085 is very important. The ratio 7080/6830 is a probe of the far UV.

Low resolution spectra are welcome, with always the same guidelines : good atmospheric correction and flux calibrated spectra is possible.
Steve suggests : near IR for monitoring O I 7772-7774, 8446 - LISA IR should be a must.

All the best,

François
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Re: Call for monitoring of AG Dra by R. Galis & al.

Postby Olivier GARDE » Thu Apr 13, 2017 9:37 am

Evolution of the Raman and HeI lines on 3 observations performed at 1 week intervals. (corrected from heliocentric velocity)

Not much evolution on the Raman lines, HeI 7065 increase regularly

Image

Image
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
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