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AuthorTitleYearJournal/ProceedingsReftypeDOI/URL
Teyssier, F. CI Cygni 2010 Outburst and Eclipse: An Amateur Spectroscopic Survey - First Results From Low Resolution Spectra 2011 Journal of the American Association of Variable Star Observers (JAAVSO)
Vol. 39, pp. 41 
article URL 
Abstract: The aim of this document is to present the amateur spectroscopic survey
of the 2010 outburst of symbiotic star CI Cygni by Christian Buil,
Thierry Garrel, Benjamin Mauclaire, François Teyssier, Eric Sarrazin,
and Pierre Dubreuil (ARAS - Astronomical Ring for Access to
Spectroscopy). This outburst coincides with an eclipse of the hot
component by the late-type giant star. After a brief review of the
current knowledge of this system, the campaign is presented. The first
results obtained from low-resolution spectra are described: main
emission lines (equivalent width and absolute flux) and continuum
evolution in comparison with the CCD V light curve obtained by AAVSO
observers.
BibTeX:
@article{,
  author = {Teyssier, F.},
  title = {CI Cygni 2010 Outburst and Eclipse: An Amateur Spectroscopic Survey - First Results From Low Resolution Spectra},
  journal = {Journal of the American Association of Variable Star Observers (JAAVSO)},
  year = {2011},
  volume = {39},
  pages = {41},
  url = {https://ui.adsabs.harvard.edu/abs/2011JAVSO..39...41T}
}
Iłkiewicz, K., Mikołajewska, J., Stoyanov, K., Manousakis, A. and Miszalski, B. Active phases and flickering of a symbiotic recurrent nova T CrB 2016 Monthly Notices of the Royal Astronomical Society
Vol. 462, pp. 2695-2705 
article URL 
Abstract: T CrB is a symbiotic recurrent nova known to exhibit active phases,
characterized by apparent increases in the hot component temperature and
the appearance of flickering, I.e. changes in the observed flux on the
time-scale of minutes. Historical UV observations have ruled out orbital
variability as an explanation for flickering and instead suggest
flickering is caused by variable mass transfer. We have analysed optical
and X-ray observations to investigate the nature of the flickering as
well as the active phases in T CrB. The spectroscopic and photometric
observations confirm that the active phases follow two periods of ̃1000d
and ̃5000d. Flickering in the X-rays is detected and follows an
amplitude-flux relationship similar to that observed in the optical. The
flickering is most prominent at harder X-ray energies, suggesting that
it originates in the boundary layer between the accretion disc and the
white dwarf. The X-ray radiation from the boundary layer is then
reprocessed by a thick accretion disc or a nebula into UV radiation. A
more detailed understanding of flickering would benefit from long-term
simultaneous X-ray and optical monitoring of the phenomena in symbiotic
recurrent novae and related systems such as Z And type symbiotic stars.
BibTeX:
@article{,
  author = {Iłkiewicz, Krystian and Mikołajewska, Joanna and Stoyanov, Kiril and Manousakis, Antonios and Miszalski, Brent},
  title = {Active phases and flickering of a symbiotic recurrent nova T CrB},
  journal = {Monthly Notices of the Royal Astronomical Society},
  year = {2016},
  volume = {462},
  pages = {2695--2705},
  url = {https://ui.adsabs.harvard.edu/abs/2016MNRAS.462.2695I}
}
Ramsay, G., Sokoloski, J.L., Luna, G.J.M. and Nuñez, N.E. Swift observations of the 2015 outburst of AG Peg - from slow nova to classical symbiotic outburst 2016 Monthly Notices of the Royal Astronomical Society
Vol. 461, pp. 3599-3606 
article URL 
Abstract: Symbiotic stars often contain white dwarfs with quasi-steady shell
burning on their surfaces. However, in most symbiotics, the origin of
this burning is unclear. In symbiotic slow novae, however, it is linked
to a past thermonuclear runaway. In 2015 June, the symbiotic slow nova
AG Peg was seen in only its second optical outburst since 1850. This
recent outburst was of much shorter duration and lower amplitude than
the earlier eruption, and it contained multiple peaks - like outbursts
in classical symbiotic stars such as Z And. We report Swift X-ray and UV
observations of AG Peg made between 2015 June and 2016 January. The
X-ray flux was markedly variable on a time-scale of days, particularly
during four days near optical maximum, when the X-rays became bright and
soft. This strong X-ray variability continued for another month, after
which the X-rays hardened as the optical flux declined. The UV flux was
high throughout the outburst, consistent with quasi-steady shell burning
on the white dwarf. Given that accretion discs around white dwarfs with
shell burning do not generally produce detectable X-rays (due to
Compton-cooling of the boundary layer), the X-rays probably originated
via shocks in the ejecta. As the X-ray photoelectric absorption did not
vary significantly, the X-ray variability may directly link to the
properties of the shocked material. AG Peg's transition from a slow
symbiotic nova (which drove the 1850 outburst) to a classical symbiotic
star suggests that shell burning in at least some symbiotic stars is
residual burning from prior novae.
BibTeX:
@article{,
  author = {Ramsay, Gavin and Sokoloski, J. L. and Luna, G. J. M. and Nuñez, N. E.},
  title = {Swift observations of the 2015 outburst of AG Peg - from slow nova to classical symbiotic outburst},
  journal = {Monthly Notices of the Royal Astronomical Society},
  year = {2016},
  volume = {461},
  pages = {3599--3606},
  url = {https://ui.adsabs.harvard.edu/abs/2016MNRAS.461.3599R}
}
Merc, J., Gális, R. and Leedjärv, L. Recent outburst activity of the symbiotic binary AG Draconis 2017 The Golden Age of Cataclysmic Variables and Related Objects IV  inproceedings URL 
Abstract: The symbiotic binary AG Dra regularly undergoes quiescent and active
stages which consist of several outbursts repeating with about 360d
interval. The recent outburst activity of AG Dra started by the minor
outburst in the late spring of 2015 and was definitely confirmed by the
outbursts in April 2016 and May 2017. In the presented work, the
photometric and spectroscopic behaviour of the recent outburst activity
of AG Dra is presented in detail. Moreover, the temperature of the white
dwarf in AG Dra is studied based on the behaviour of the prominent
emission lines. We show that a disentanglement of particular effects in
the observed changes of the emission lines is crucial to investigate the
intrinsic white dwarf temperature variations related to outburst
activity of this strongly interacting binary. We also report the effects
of the low excitation lines orbital variations and of the Hβ absorption
component on their equivalent widths as well as consequences of the
approximations used in our previous works.
BibTeX:
@inproceedings{,
  author = {Merc, J. and Gális, R. and Leedjärv, L.},
  title = {Recent outburst activity of the symbiotic binary AG Draconis},
  booktitle = {The Golden Age of Cataclysmic Variables and Related Objects IV},
  year = {2017},
  url = {https://ui.adsabs.harvard.edu/abs/2017gacv.workE..60M}
}
Skopal, A., Shugarov, S.Y., Sekeráš, M., Wolf, M., Tarasova, T.N., Teyssier, F., Fujii, M., Guarro, J., Garde, O., Graham, K., Lester, T., Bouttard, V., Lemoult, T., Sollecchia, U., Montier, J. and Boyd, D. New outburst of the symbiotic nova AG Pegasi after 165 yr 2017 Astronomy and Astrophysics
Vol. 604 
article URL 
Abstract: Context. AG Peg is known as the slowest symbiotic nova, which
experienced its nova-like outburst around 1850. After 165 yr, during
June of 2015, it erupted again showing characteristics of the Z And-type
outburst.
Aims: The primary objective is to determine basic
characteristics, the nature and type of the 2015 outburst of AG Peg. /> Methods: We achieved this aim by modelling the spectral energy
distribution using low-resolution spectroscopy (330-750 nm; R =
500-1000), medium-resolution spectroscopy (420-720 nm; R 11 000), and
UBVRCIC photometry covering the 2015 outburst with
a high cadence. Optical observations were complemented with the archival
HST and FUSE spectra from the preceding quiescence.
Results:
During the outburst, the luminosity of the hot component was in the
range of 2-11 × 1037 (d/ 0.8 kpc)2 erg
s-1, being in correlation with the light curve (LC) profile.
To generate the maximum luminosity by the hydrogen burning, the white
dwarf (WD) had to accrete at 3 × 10-7 M
yr-1, which exceeds the stable-burning limit and thus led to
blowing optically thick wind from the WD. We determined its mass-loss
rate to a few × 10-6 M yr-1. At the
high temperature of the ionising source, 1.5-2.3 × 105 K, the
wind converted a fraction of the WD's photospheric radiation into the
nebular emission that dominated the optical. A one order of magnitude
increase of the emission measure, from a few × 1059 (d/ 0.8
kpc)2 cm-3 during quiescence, to a few ×
1060 (d/ 0.8 kpc)2 cm-3 during the
outburst, caused a 2 mag brightening in the LC, which is classified as
the Z And-type of the outburst.
Conclusions: The very high
nebular emission and the presence of a disk-like H I region encompassing
the WD, as indicated by a significant broadening and high flux of the
Raman-scattered O vi 6825 Å line during the outburst, is consistent with
the ionisation structure of hot components in symbiotic stars during
active phases. Full Table 1 and Table 6 are only available at the CDS
are available at the CDS via anonymous ftp to href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr (href="http://130.79.128.5">http://130.79.128.5) or via href="http://cdsarc.u-strasbg.fr/viz-
bin/qcat?J/A+A/604/A48">http://cdsarc.u-strasbg.fr/viz-
bin/qcat?J/A+A/604/A48
BibTeX:
@article{,
  author = {Skopal, A. and Shugarov, S. Yu. and Sekeráš, M. and Wolf, M. and Tarasova, T. N. and Teyssier, F. and Fujii, M. and Guarro, J. and Garde, O. and Graham, K. and Lester, T. and Bouttard, V. and Lemoult, T. and Sollecchia, U. and Montier, J. and Boyd, D.},
  title = {New outburst of the symbiotic nova AG Pegasi after 165 yr},
  journal = {Astronomy and Astrophysics},
  year = {2017},
  volume = {604},
  url = {https://ui.adsabs.harvard.edu/abs/2017A&A...604A..48S}
}
Schmid, H.M., Bazzon, A., Milli, J., Roelfsema, R., Engler, N., Mouillet, D., Lagadec, E., Sissa, E., Sauvage, J.F., Ginski, C., Baruffolo, A., Beuzit, J.L., Boccaletti, A., Bohn, A.J., Claudi, R., Costille, A., Desidera, S., Dohlen, K., Dominik, C., Feldt, M., Fusco, T., Gisler, D., Girard, J.H., Gratton, R., Henning, T., Hubin, N., Joos, F., Kasper, M., Langlois, M., Pavlov, A., Pragt, J., Puget, P., Quanz, S.P., Salasnich, B., Siebenmorgen, R., Stute, M., Suarez, M., Szulágyi, J., Thalmann, C., Turatto, M., Udry, S., Vigan, A. and Wildi, F. SPHERE/ZIMPOL observations of the symbiotic system R Aquarii. I. Imaging of the stellar binary and the innermost jet clouds 2017 Astronomy and Astrophysics
Vol. 602 
article URL 
Abstract: Context. R Aqr is a symbiotic binary system consisting of a mira
variable, a hot companion with a spectacular jet outflow, and an
extended emission line nebula. Because of its proximity to the Sun, this
object has been studied in much detail with many types of high
resolution imaging and interferometric techniques. We have used R Aqr as
test target for the visual camera subsystem ZIMPOL, which is part of the
new extreme adaptive optics (AO) instrument SPHERE at the Very Large
Telescope (VLT).
Aims: We describe SPHERE/ZIMPOL test
observations of the R Aqr system taken in Hα and other filters in order
to demonstrate the exceptional performance of this high resolution
instrument. We compare our observations with data from the Hubble Space
Telescope (HST) and illustrate the complementarity of the two
instruments. We use our data for a detailed characterization of the
inner jet region of R Aqr.
Methods: We analyze the high
resolution ≈ 25 mas images from SPHERE/ZIMPOL and determine from the Hα
emission the position, size, geometric structure, and line fluxes of the
jet source and the clouds in the innermost region <2'' (<400 AU)
of R Aqr. The data are compared to simultaneous HST line filter
observations. The Hα fluxes and the measured sizes of the clouds yield
Hα emissivities for many clouds from which one can derive the mean
density, mass, recombination time scale, and other cloud parameters. /> Results: Our Hα data resolve for the first time the R Aqr binary and
we measure for the jet source a relative position 45 mas West (position
angle -89.5°) of the mira. The central jet source is the strongest Hα
component with a flux of about 2.5 × 10-12 erg
cm-2 s-1. North east and south west from the
central source there are many clouds with very diverse structures.
Within 0.5'' (100 AU) we see in the SW a string of bright clouds
arranged in a zig-zag pattern and, further out, at 1''-2'', fainter and
more extended bubbles. In the N and NE we see a bright, very elongated
filamentary structure between 0.2''-0.7'' and faint perpendicular
"wisps" further out. Some jet clouds are also detected in the ZIMPOL [O
I] and He I filters, as well as in the HST-WFC3 line filters for Hα, [O
III], [N II], and [O I]. We determine jet cloud parameters and find a
very well defined correlation Ne ∝ r-1.3 between
cloud density and distance to the central binary. Densities are very
high with typical values of Ne ≈ 3 × 105
cm-3 for the "outer" clouds around 300 AU, Ne ≈ 3
× 106 cm-3 for the "inner" clouds around 50 AU,
and even higher for the central jet source. The high Ne of
the clouds implies short recombination or variability timescales of a
year or shorter.
Conclusions: Hα high resolution data provide a
lot of diagnostic information for the ionized jet gas in R Aqr. Future
Hα observations will provide the orientation of the orbital plane of the
binary and allow detailed hydrodynamical investigations of this jet
outflow and its interaction with the wind of the red giant companion.
The reduced Hα image given in Fig. 6 is only available at the CDS via
anonymous ftp to href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr (href="http://130.79.128.5">http://130.79.128.5) or via href="http://cdsarc.u-strasbg.fr/viz-
bin/qcat?J/A+A/602/A53">http://cdsarc.u-strasbg.fr/viz-
bin/qcat?J/A+A/602/A53
BibTeX:
@article{,
  author = {Schmid, H. M. and Bazzon, A. and Milli, J. and Roelfsema, R. and Engler, N. and Mouillet, D. and Lagadec, E. and Sissa, E. and Sauvage, J. F. and Ginski, C. and Baruffolo, A. and Beuzit, J. L. and Boccaletti, A. and Bohn, A. J. and Claudi, R. and Costille, A. and Desidera, S. and Dohlen, K. and Dominik, C. and Feldt, M. and Fusco, T. and Gisler, D. and Girard, J. H. and Gratton, R. and Henning, T. and Hubin, N. and Joos, F. and Kasper, M. and Langlois, M. and Pavlov, A. and Pragt, J. and Puget, P. and Quanz, S. P. and Salasnich, B. and Siebenmorgen, R. and Stute, M. and Suarez, M. and Szulágyi, J. and Thalmann, C. and Turatto, M. and Udry, S. and Vigan, A. and Wildi, F.},
  title = {SPHERE/ZIMPOL observations of the symbiotic system R Aquarii. I. Imaging of the stellar binary and the innermost jet clouds},
  journal = {Astronomy and Astrophysics},
  year = {2017},
  volume = {602},
  url = {https://ui.adsabs.harvard.edu/abs/2017A&A...602A..53S}
}
Lucy, A.B., Sokoloski, J.L., Nuñez, N.E., Wolf, C., Bohlsen, T. and Luna, G.J.M. Discovery of a Hot Symbiotic Star in the Cold Antarctic Sky: Symbiotics Are Outliers in SkyMapper uvgriz Photometry 2018 Research Notes of the American Astronomical Society
Vol. 2 
article URL 
BibTeX:
@article{,
  author = {Lucy, Adrian B. and Sokoloski, J. L. and Nuñez, N. E. and Wolf, C. and Bohlsen, T. and Luna, G. J. M.},
  title = {Discovery of a Hot Symbiotic Star in the Cold Antarctic Sky: Symbiotics Are Outliers in SkyMapper uvgriz Photometry},
  journal = {Research Notes of the American Astronomical Society},
  year = {2018},
  volume = {2},
  url = {https://ui.adsabs.harvard.edu/abs/2018RNAAS...2d.229L}
}
Teyssier, F., Boyd, D., Guarro, J., Sims, F., Lester, T., Foster, J., Berardi, P., Bohlsen, T., Buil, C., Sollecchia, U., Somogyi, P., Bazan, K., Boussier, H., Boussin, C., Buchet, Y., Campos, F., Cazzato, P., Charbonnel, S., Dubreuil, P., Franco, L., Garde, O., Graham, K., Martineau, G., Montier, J., Rodda, T. and Verlinden, M. Spectroscopic observations of symbiotic stars in 2018-Q3 2018 Eruptive Stars Information Letter
Vol. 39, pp. 19-101 
article URL 
Abstract: We present spectroscopic observations (R = 500 to 15000) of 26 Symbiotic
Stars during 2018, 3rd quarter. HbHa1705-04 has been detected in
outburst by R. Fidrich and identified as a Symbiotic star by Poalo
Berardi. The star has been monitored during the decline. AS 289 has been
detected in cool outburst (vanishing of the high ionized lines [Fe
VII]). CH Cyg fades in July before recovering. The event has been
monitored at high cadency, especillay with Echelle spectra at R = 9000
to 13000. Peter Somogyi detected peculiar emission line profiles of MWC
560, with a lack of the typical absorption in the blue part of Balmer
and Fe II lines. The terminal velocity of Balmer lines is -1000 km.s-1
with a classical P Cygni absorption which peaks at -190 for Ha and -200
to -220 km.s-1 for Hb. Z And is declining after Februray, 2018 outburst.
Raman OVI bands reappear late after [Fe VII].
BibTeX:
@article{,
  author = {Teyssier, F. and Boyd, D. and Guarro, J. and Sims, F. and Lester, T. and Foster, J. and Berardi, P. and Bohlsen, T. and Buil, C. and Sollecchia, U. and Somogyi, P. and Bazan, K. and Boussier, H. and Boussin, C. and Buchet, Y. and Campos, F. and Cazzato, P. and Charbonnel, S. and Dubreuil, P. and Franco, L. and Garde, O. and Graham, K. and Martineau, G. and Montier, J. and Rodda, T. and Verlinden, M.},
  title = {Spectroscopic observations of symbiotic stars in 2018-Q3},
  journal = {Eruptive Stars Information Letter},
  year = {2018},
  volume = {39},
  pages = {19--101},
  url = {https://ui.adsabs.harvard.edu/abs/2018ESIL...39...19T}
}
Ilkiewicz, K., Mikolajewska, J., Stoyanov, K., Manousakis, A. and Miszalski, B. VizieR Online Data Catalog: Symbiotic recurrent nova T CrB spectroscopy (Ilkiewicz+, 2016) 2018 VizieR Online Data Catalog  article URL 
Abstract: Spectroscopic observations were obtained from the Astronomical Ring for
Access to Spectroscopy data base (ARAS, http://www.astrosurf.com/aras/).
(3 data files).
BibTeX:
@article{,
  author = {Ilkiewicz, K. and Mikolajewska, J. and Stoyanov, K. and Manousakis, A. and Miszalski, B.},
  title = {VizieR Online Data Catalog: Symbiotic recurrent nova T CrB spectroscopy (Ilkiewicz+, 2016)},
  journal = {VizieR Online Data Catalog},
  year = {2018},
  url = {https://ui.adsabs.harvard.edu/abs/2018yCat..74622695I}
}
Teyssier, F. Long Term Spectroscopic Monitoring of the Brightest Symbiotic Stars (Abstract) 2018 Journal of the American Association of Variable Star Observers (JAAVSO)
Vol. 46, pp. 190 
article URL 
Abstract: (Abstract only) Symbiotic stars are wide interacting binary systems
comprising a cool giant and a hot compact star, mostly a white dwarf,
accreting from the giant's wind. Their orbital periods are hundreds of
days (for S-type systems containing a normal giant). The accreting WD
represents a strong source of ultraviolet radiation that ionizes a
fraction of the wind from the giant and produces a rich emission
spectrum. They are strongly variable, according to orbital phase and
activity, and can produce various types of outbursts. Symbiotic stars
are considered as excellent laboratories for studying a variety of
astrophysical problems, such as wind from red giants, accretion -
eventually throw a disk - thermonuclear outbursts under a wide range of
conditions, collimation of stellar wind, formation of jets, etc. About
50 symbiotic stars in the galaxy are bright enough to be studied by
amateur spectroscopy with small telescopes ranging from 8 to 24 inches.
We have undergone a long-term monitoring program in the visual range of
the brightest symbiotics at a resolution from 500 to 15,000. A part of
this program is performed in collaboration with or upon the request of
professional teams, feeding several publications at least partially (for
instance: T CrB, AG Peg, AG Dra).
BibTeX:
@article{,
  author = {Teyssier, F.},
  title = {Long Term Spectroscopic Monitoring of the Brightest Symbiotic Stars (Abstract)},
  journal = {Journal of the American Association of Variable Star Observers (JAAVSO)},
  year = {2018},
  volume = {46},
  pages = {190},
  url = {https://ui.adsabs.harvard.edu/abs/2018JAVSO..46..190T}
}
Munari, U., Dallaporta, S., Valisa, P., Ochner, P., Fidrich, R., Berardi, P., Garde, O. and Buil, C. HBHa 1704-05: a bright and newly discovered symbiotic star, currently undergoing an "hot-type" outburst 2018 The Astronomer's Telegram
Vol. 11937, pp. 1 
article URL 
Abstract: HBHa 1704-05 was first noted by Kohoutek and Wehmeyer in their catalog
of emission line stars (1999, A & AS, 134, 255), as a source with a
strong continuum (thus not a PN) and overexposed Halpha emission.
BibTeX:
@article{,
  author = {Munari, U. and Dallaporta, S. and Valisa, P. and Ochner, P. and Fidrich, R. and Berardi, P. and Garde, O. and Buil, C.},
  title = {HBHa 1704-05: a bright and newly discovered symbiotic star, currently undergoing an "hot-type" outburst},
  journal = {The Astronomer's Telegram},
  year = {2018},
  volume = {11937},
  pages = {1},
  url = {https://ui.adsabs.harvard.edu/abs/2018ATel11937....1M}
}
Merc, J., Gális, R. and Teyssier, F. Study of long-term spectroscopic variability of symbiotic stars based on observations of the ARAS Group 2019 Contributions of the Astronomical Observatory Skalnate Pleso
Vol. 49, pp. 228-235 
article URL 
Abstract: The importance of small-telescope observations is demonstrated by
investigation of long-term outburst activity of the symbiotic systems AG
Dra, Z And and AG Peg based on spectroscopic measurements obtained by
amateur astronomers organized in the Astronomical Ring for Amateur
Spectroscopy. Preliminary results of our ongoing spectroscopic campaign
focused on AG Dra are presented. The temperature of the white dwarf is
studied based on behaviour of the prominent emission lines, which are
well detectable even in low-resolution spectra. The activity of AG Dra
is compared to that of two other symbiotic systems - Z And and AG Peg,
which have shown outbursts recently. Z And is a prototype of classical
symbiotic stars which manifested the outburst at the turn of the years
2017 and 2018. AG Peg is the slowest symbiotic nova with the Z And-type
outburst in 2015, 165 years after its nova-like flare-up.
BibTeX:
@article{,
  author = {Merc, J. and Gális, R. and Teyssier, F.},
  title = {Study of long-term spectroscopic variability of symbiotic stars based on observations of the ARAS Group},
  journal = {Contributions of the Astronomical Observatory Skalnate Pleso},
  year = {2019},
  volume = {49},
  pages = {228--235},
  url = {https://ui.adsabs.harvard.edu/abs/2019CoSka..49..228M}
}
Lucy, A.B., Sokoloski, J.L., Munari, U., Roy, N., Kuin, N.P.M., Rupen, M.P., Knigge, C., Darnley, M.J., Luna, G.J.M., Somogyi, P., Valisa, P., Milani, A., Sollecchia, U. and Weston, J.H.S. Regulation of accretion by its outflow in a symbiotic star: the 2016 outflow fast state of MWC 560 2019 arXiv e-prints  misc URL 
Abstract: The symbiotic binary MWC 560 (=V694 Mon) is a laboratory for the complex
relationship between an accretion disk and its outflow. In 2016, at the
peak of a slow rise in optical flux, the maximum velocity of the broad
absorption line outflow abruptly doubled to at least 2500 km s^-1.
The sudden onset of high-velocity Balmer absorption coincided with
remarkable developments indicating an increase in outflow power:
optically-thin thermal radio emission began rising by about 20
μJy/month, and soft X-ray flux increased by an order of magnitude.
Comparison to historical data suggests that both high-velocity and low-
velocity optical outflow components must be simultaneously present to
yield a large soft X-ray flux, which may originate in a shock where
these fast and slow absorbers collide. Balmer absorption and the
enduring Fe II ultraviolet absorption curtain demonstrate that the
absorption line-producing outflow was consistently fast and dense
(0^6.5 cm^-3) throughout the 2016 outflow fast state,
steadily feeding a lower-density (0^5.5 cm^-3) region
of radio-emitting gas. Persistent optical and near-ultraviolet
flickering indicates that the accretion disk remained intact, and that
the increase in optical brightness was due to an increase in the rate of
accretion through the disk. The stability of all these properties in
2016 stands in marked contrast to dramatic variations during the 1990
optical brightening event of MWC 560, despite reaching a similar
accretion luminosity. We propose that accretion state changes in MWC
560, such as evacuation of the inner disk, are sometimes prevented by
the self-regulatory effect of the disk's outflow.
BibTeX:
@misc{,
  author = {Lucy, Adrian B. and Sokoloski, J. L. and Munari, U. and Roy, Nirupam and Kuin, N. Paul M. and Rupen, Michael P. and Knigge, Christian and Darnley, M. J. and Luna, G. J. M. and Somogyi, Péter and Valisa, P. and Milani, A. and Sollecchia, U. and Weston, Jennifer H. S.},
  title = {Regulation of accretion by its outflow in a symbiotic star: the 2016 outflow fast state of MWC 560},
  booktitle = {arXiv e-prints},
  year = {2019},
  url = {https://ui.adsabs.harvard.edu/abs/2019arXiv190502399L}
}
Merc, J., Gális, R., Wolf, M., Leedjärv, L. and Teyssier, F. The activity of the symbiotic binary Z Andromedae and its latest outburst 2019 Open European Journal on Variable Stars
Vol. 197, pp. 23 
article URL 
Abstract: Z Andromedae is a prototype of classical symbiotic variable stars. It is
characterized by alternating of quiescent and active stages, the later
ones are accompanied by changes in both photometry and spectral
characteristics of this object. The current activity of Z And began in
2000, and the last outburst was recorded at the turn of years 2017 and
2018. An important source of information about the behaviour of this
symbiotic binary during the ongoing active stage is photometric and
spectroscopic observations obtained with small telescopes by amateur
astronomers. In this paper, we present the results of analysis of these
observations, with an emphasis on the significant similarity of the last
outburst of Z And with the previous ones, during which jets from this
symbiotic system were observed. The presented results point to the
importance of long-term monitoring of symbiotic binaries.
BibTeX:
@article{,
  author = {Merc, J. and Gális, R. and Wolf, M. and Leedjärv, L. and Teyssier, F.},
  title = {The activity of the symbiotic binary Z Andromedae and its latest outburst},
  journal = {Open European Journal on Variable Stars},
  year = {2019},
  volume = {197},
  pages = {23},
  url = {https://ui.adsabs.harvard.edu/abs/2019OEJV..197...23M}
}
Gális, R., Merc, J., Leedjärv, L., Vrašťák, M. and Karpov, S. The peculiar outburst activity of the symbiotic binary AG Draconis 2019 Open European Journal on Variable Stars
Vol. 197, pp. 15 
article URL 
Abstract: AG Draconis is a strongly interacting binary system which manifests
characteristic symbiotic activity of alternating quiescent and active
stages. The latter ones consist of the series of individual outbursts
repeating at about a one-year interval. After seven years of flat
quiescence following the 2006-2008 major outbursts, in the late spring
of 2015, the symbiotic system AG Dra started to become brighter again
toward what appeared to be a new minor outburst. The current outburst
activity of AG Dra was confirmed by the following three outbursts in
April 2016, May 2017 and April 2018. The photometric and spectroscopic
observations suggest that all these outbursts are of the hottype. Such
behaviour is considerablypeculiar in almost 130-year history of
observing of this object, because the major outbursts at the beginning
of active stages are typically coolones. In the present work, the
current peculiar activity of the symbiotic binary AG Dra is describedin
detail.
BibTeX:
@article{,
  author = {Gális, R. and Merc, J. and Leedjärv, L. and Vrašťák, M. and Karpov, S.},
  title = {The peculiar outburst activity of the symbiotic binary AG Draconis},
  journal = {Open European Journal on Variable Stars},
  year = {2019},
  volume = {197},
  pages = {15},
  url = {https://ui.adsabs.harvard.edu/abs/2019OEJV..197...15G}
}
Shagatova, N., Skopal, A., Sekeráš, M., Teyssier, F., Shugarov, S.Y., Komžík, R., Garai, Z., Kundra, E. and Vaňko, M. Hα orbital variations of the symbiotic star EG And from optical spectroscopy 2019 Contributions of the Astronomical Observatory Skalnate Pleso
Vol. 49, pp. 406-410 
article URL 
Abstract: In this contribution, we explore the orbital variability of the Hα-line
emission and absorption components of the symbiotic system EG And. We
have found that the equivalent width of the core emission is the largest
at the orbital phase φ ≈ 0.4 and the smallest at φ ≈ 0.2. This probably
reflects an asymmetric distribution of the cool giant wind at the
orbital-plane area. Furthermore, the core emission equivalent width has
a secondary maximum at φ ≈ 0.1. The strongest absorption in the profile
is measured around the inferior conjunction of the white dwarf, φ
&approx 0.4. This suggests that the ionized region is partially
optically thick in the Hα line.
BibTeX:
@article{,
  author = {Shagatova, N. and Skopal, A. and Sekeráš, M. and Teyssier, F. and Shugarov, S. Yu. and Komžík, R. and Garai, Z. and Kundra, E. and Vaňko, M.},
  title = {Hα orbital variations of the symbiotic star EG And from optical spectroscopy},
  journal = {Contributions of the Astronomical Observatory Skalnate Pleso},
  year = {2019},
  volume = {49},
  pages = {406--410},
  url = {https://ui.adsabs.harvard.edu/abs/2019CoSka..49..406S}
}
Teyssier, F., Boyd, D., Guarro, J., Sims, F., Campos, F., Lester, T., Sollecchia, U., Boussin, C., Charbonnel, S., Garde, O., Somogyi, P., Buil, C., Berardi, P., Marik, V., Martineau, G., Buchet, Y., Diarrassouba, I. and Michelet, J. Spectroscopic observations of symbiotic stars in 2019-Q1 2019 Eruptive Stars Information Letter
Vol. 41, pp. 2-75 
article URL 
Abstract: 198 spectra of 23 symbiotic stars at resolution from 500 to 15000 were
obtained during 2019-Q1 by 18 observers. AG Dra is monitored before the
expected outburst in 2019. At the current date (2019-05-18) no sign of
outburst has been detected. From medium resolution spectra we have
detected the appearence of an emission line in the red edge of He I 5016
during outbursts. The identification of the line is discussed. AX Per
soon after the end of its eclipse has been detected in strong classical
outburst, characterized by the weakening of high emission lines [Fe
VII]. CH Cyg is in low luminosity, several spectra have been obtained
during a short flare. V694 Mon, in high luminosity, has been monitored
at high cadence during the season. The profiles of Balmer and Fe II
lines is unusual, showing a classical P Cygni profile and the
disappearance of the broad blue absorption lines.
BibTeX:
@article{,
  author = {Teyssier, F. and Boyd, D. and Guarro, J. and Sims, F. and Campos, F. and Lester, T. and Sollecchia, U. and Boussin, C. and Charbonnel, S. and Garde, O. and Somogyi, P. and Buil, C. and Berardi, P. and Marik, V. and Martineau, G. and Buchet, Y. and Diarrassouba, I. and Michelet, J.},
  title = {Spectroscopic observations of symbiotic stars in 2019-Q1},
  journal = {Eruptive Stars Information Letter},
  year = {2019},
  volume = {41},
  pages = {2--75},
  url = {https://ui.adsabs.harvard.edu/abs/2019ESIL...41....2T}
}
Merc, J., Galis, R., Teyssier, F., Boyd, D., Sims, W., Boussin, C. and Campos, F. The symbiotic star AX Per is going into strong outburst 2019 The Astronomer's Telegram
Vol. 12660, pp. 1 
article URL 
Abstract: 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.
BibTeX:
@article{,
  author = {Merc, J. and Galis, R. and Teyssier, F. and Boyd, D. and Sims, W. and Boussin, C. and Campos, F.},
  title = {The symbiotic star AX Per is going into strong outburst},
  journal = {The Astronomer's Telegram},
  year = {2019},
  volume = {12660},
  pages = {1},
  url = {https://ui.adsabs.harvard.edu/abs/2019ATel12660....1M}
}
Teyssier, F., Boyd, D., Guarro, J., Sims, F., Foster, J., Somogyi, P., Berardi, P., Sollecchia, U., Charbonnel, S., Bohlsen, T., Campos, F., Martineau, G., Buchet, Y., Graham, K., Boussin, C., Boubault, F., Franco, L., Rodda, T., Marik, V., Buil, C., Kantola, T. and Coffin, J. Spectroscopic observations of symbiotic stars in 2018-Q4 2019 Eruptive Stars Information Letter
Vol. 40, pp. 4-75 
article URL 
Abstract: 202 spectra of 26 symbiotic stars at resolution from 500 to 15000 were
obtained during 2018-Q4. AG Dra has recovered its quiescent state after
April 2018 outburst. CH Cyg has been monitoring at a high cadency during
its monotonically decline from mag V = 6.4 early august to V = 8.5. More
than 700 spectra of CH Cygni are now gathered in the database. First
spectrum of the poorly studied EF Aql in the database. Spectra of the
new symbiotic Hen 3-1768 detected within the context of the program
"suspected symbiotic stars" show strong He II l 4686 and Raman OVI 6830.
The new symbiotic star HbHa 1704-058 observed during its decline show
increasing raman OVI band (EW = -3.3) while [OIII] and [Fe VII] remain
very weak if present. V694 Mon, at high luminosity (V 9) , presents
unusual shape of Balmer and Fe II lines: the common broad absorption is
replaced by P Cygni profiles at much lower velocities (maximum of
absorption -100 km s-1). The prototypical Z And returns to quiescent
state after the outburst which occurred in January 2018.
BibTeX:
@article{,
  author = {Teyssier, F. and Boyd, D. and Guarro, J. and Sims, F. and Foster, J. and Somogyi, P. and Berardi, P. and Sollecchia, U. and Charbonnel, S. and Bohlsen, T. and Campos, F. and Martineau, G. and Buchet, Y. and Graham, K. and Boussin, C. and Boubault, F. and Franco, L. and Rodda, T. and Marik, V. and Buil, C. and Kantola, T. and Coffin, J.},
  title = {Spectroscopic observations of symbiotic stars in 2018-Q4},
  journal = {Eruptive Stars Information Letter},
  year = {2019},
  volume = {40},
  pages = {4--75},
  url = {https://ui.adsabs.harvard.edu/abs/2019ESIL...40L...4T}
}
Skopal, A., Sekeráš, M., Kundra, E., Komžík, R., Shugarov, S.Y., Buil, C., Berardi, P. and Zubareva, A. First glance at the recently discovered symbiotic star HBHA 1704-05 during its current outburst 2019 Contributions of the Astronomical Observatory Skalnate Pleso
Vol. 49, pp. 424-426 
article URL 
Abstract: In this contribution we introduce our photometric and spectroscopic
observations of the newly (August 9, 2018) discovered outburst of the
emission-line star, HBHA 1704-05, whose photometric variability and the
spectrum during the outburst are both characteristic for a symbiotic
star.
BibTeX:
@article{,
  author = {Skopal, A. and Sekeráš, M. and Kundra, E. and Komžík, R. and Shugarov, S. Yu. and Buil, C. and Berardi, P. and Zubareva, A.},
  title = {First glance at the recently discovered symbiotic star HBHA 1704-05 during its current outburst},
  journal = {Contributions of the Astronomical Observatory Skalnate Pleso},
  year = {2019},
  volume = {49},
  pages = {424--426},
  url = {https://ui.adsabs.harvard.edu/abs/2019CoSka..49..424S}
}
Skopal, A. Studying symbiotic stars and classical nova outbursts with small telescopes 2019 Contributions of the Astronomical Observatory Skalnate Pleso
Vol. 49, pp. 189-196 
article URL 
Abstract: Symbiotic stars are the widest interacting binaries, whose orbital
periods are of the order of years, or even more, while cataclysmic
variables are interacting binaries with periods of a few hours. Both
systems comprise a white dwarf as the accretor, and undergo
unpredictable outbursts. Using the multicolour photometry and optical
spectroscopy obtained with small telescopes, I present examples of the
white dwarf outburst in a cataclysmic variable, the classical nova V339
Del, and that in the symbiotic star AG Peg. In this way I highlight
importance of observations of bright outbursts using small telescopes.
BibTeX:
@article{,
  author = {Skopal, A.},
  title = {Studying symbiotic stars and classical nova outbursts with small telescopes},
  journal = {Contributions of the Astronomical Observatory Skalnate Pleso},
  year = {2019},
  volume = {49},
  pages = {189--196},
  url = {https://ui.adsabs.harvard.edu/abs/2019CoSka..49..189S}
}
Teyssier, F. Eruptive stars monitoring and the ARAS database 2019 Contributions of the Astronomical Observatory Skalnate Pleso
Vol. 49, pp. 217-227 
article URL 
Abstract: Spectroscopic monitoring of eruptive stars (e.g. symbiotic binaries,
classical novae) by amateurs around the world, in both the northern and
southern hemispheres, is a fundamental activity of the ARAS
(Astronomical Ring for Amateur Spectroscopy) initiative. The group of
volunteers demonstrates what can be accomplished with a network of
independent, very small telescopes (from 20 to 60 cm), furnished with
spectrographs of different resolution, from ̃500 to ̃15000, and covering
the range from 3600 to nearly 8000 Å. Acquisition, reduction and
analysis of the spectra will be described. The observing program
concentrates on bright symbiotic stars (57, to date) and novae (35, to
date). The main features of the ARAS activity are rapid response to
alerts, long term monitoring and high cadence. A part of the program
involves collaborations based on requests from professional teams (e.g.
CH Cyg, AG Dra, R Aqr, SU Lyn, V339 Del) for long term monitoring or
specific events. Some examples of the evolution of basic observational
parameters during outbursts and/or as a function of orbital phase (e.g.
radial velocities, equivalent widths or line profiles) are presented.
The spectra are gathered in the open access Eruptive Stars Database that
has been used for several publications by professional teams.
BibTeX:
@article{,
  author = {Teyssier, F.},
  title = {Eruptive stars monitoring and the ARAS database},
  journal = {Contributions of the Astronomical Observatory Skalnate Pleso},
  year = {2019},
  volume = {49},
  pages = {217--227},
  url = {https://ui.adsabs.harvard.edu/abs/2019CoSka..49..217T}
}