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Alert Notice 648: Semiregular variable reclassified as symbiotic: outburst of ASASSN-V J195442.95+172212.6 = Vend47 (Sge)

August 14, 2018

Event: ASASSN-V J195442.95+172212.6 (TCP J19544251+1722281 = Vend47), originally classified as a semiregular variable, has been reclassified as a symbiotic variable as a result of its being discovered in outburst by Robert Fidrich during the course of his "Vendégcsillag-kereső" (Guest Star Hunter) nova patrol program. Subsequent spectroscopy confirmed the nature of the object as a symbiotic variable.

Discovered by: Robert Fidrich (Budapest, Hungary)

Discovery magnitude: 10.7 V (on 4 60-sec DSLR images using Canon EOS 1000D camera + 180mm focus telephoto lens)

Discovery date: 2018 August 08.9381 UT

Coordinates (2000.0): R.A. 19 54 42.95   Decl. +17 22 12.7  (from VSX)

Spectra: A spectrum obtained by Paolo Beradi (Italy) on 2018 Aug. 09.840 UT showed hydrogen and helium in emission, indicative of a symbiotic outburst, and may be seen at http://www.spectro-aras.com/forum/viewtopic.php?f=39&t=2094

Spectroscopy obtained by U. Munari et al. (ATel #11937) on 2018 Aug 10.855 UT with the Asiago 1.22m telescope and on Aug 10.882 UT with the Varese 84cm indicates the object is "a previously unknown symbiotic binary, currently undergoing an "hot-type" outburst, with the wind of the cool giant being increasingly ionized by a hot companion rising in Teff."

Additional spectra, by other observers, may be viewed at http://www.spectro-aras.com/forum/viewtopic.php?f=39&t=2094#p11302.

Observing recommendations: Observations of all types (visual, CCD, DSLR, PEP, spectroscopy) and multiple bands as instrumentation permits are strongly encouraged as the outburst progresses. Its range prior to this outburst was ~12.3-13.2V.

Observations reported to the AAVSO (including representative observations from long runs):
2018 Jul. 31.9451 UT, 12.0 V (R. Fidrich, Budapest, Hungary);
Aug. 03.9886, 11.66 V (Fidrich);
05.49, 12.35 C (ASAS database, reported by R. Fidrich);
06.3317, 11.46 V (ASAS database, reported by R. Fidrich);
08.9381, 10.7 V (Fidrich);
09.81008, 10.869 V +/-0.001 (T. Tordai, Budapest, Hungary);
09.815 Aug, 10.85 V (Tordai);
09.90359, 10.848 V +/-0.006 (T. Vanmunster, Landen, Belgium);
09.90386, 10.834 V +/-0.006 (Vanmunster);
09.90413, 10.890 V +/-0.006 (Vanmunster);
09.95833, 11.1 (A. Amorim, Florianopolis, Brazil);
10.60190, 11.45 B +/-0.06 (S. O'Connor, St. George, Bermuda);
10.60260, 10.87 V +/-0.02 (O'Connor);
10.92709, 10.5 (D. Vansteelant, Varsenare, Belgium);
10.96944, 11.0 (Amorim);
11.87500, 10.96 (X. Domingo Martinez, Alpicat, Spain);
11.89418, 10.807 V +/-0.007 (Vanmunster);
11.89444, 11.383 B +/-0.012 (Vanmunster);
11.89472, 9.050 I +/-0.008 (Vanmunster);
11.89499, 10.840 V +/-0.008 (Vanmunster);
11.89526, 11.356 B +/-0.012 (Vanmunster);
11.89554, 9.046 I +/-0.009 (Vanmunster);
11.98623, 11.0 (Fidrich);
12.05000, 11.1 (Amorim);
12.14651, 10.953 V +/-0.006 (J. Hall, Cotopaxi, CO);
12.15690, 10.925 V +/-0.006 (Hall);
12.15694, 11.2 (C. Maloney, Helena, AR);
12.15765, 10.983 V +/-0.006 (Hall);
12.19172, 10.985 V +/-0.005 (Hall);
12.33330, 10.7 (M. Komorous, London, ONT, Canada);
12.81671, 10.869 V +/-0.002 (Tordai);
12.90556, 11.0 (P. Schmeer, Saarbruecken-Bischmisheim, Germany);
13.00851, 9.127 I +/-0.017 (F.-J. Hambsch, Mol, Belgium);
13.00867, 9.150 I +/-0.017 (Hambsch);
13.00902, 11.482 B +/-0.009 (Hambsch);
13.00941, 11.468 B +/-0.009 (Hambsch);
13.00977, 10.895 V +/-0.007 (Hambsch);
13.01003, 10.884 V +/-0.007 (Hambsch);
13.02083, 11.0 (Amorim);
13.03163, 10.933 V +/-0.006 (Vanmunster);
13.03190, 11.480 B +/-0.010 (Vanmunster);
13.03217, 9.097 I +/-0.009 (Vanmunster);
13.03242, 10.913 V +/-0.007 (Vanmunster);
13.03270, 11.464 B +/-0.010 (Vanmunster);
13.03298, 9.126 I +/-0.008 (Vanmunster);
13.07010, 10.8 (Komorous);
13.16080, 11.057 V +/-0.006 (Hall);
13.16376, 11.544 B +/-0.004 (Hall);
13.21999, 11.001 V +/-0.007 (Hall);
13.22111, 11.542 B +/-0.006 (Hall);
13.83362, 10.910 V +/-0.003 (Tordai);
13.84293, 10.892 V +/-0.002 (Tordai);
13.85363, 10.797 V +/-0.012 (R. Pickard, Leominster, UK);
13.89511, 10.867 V +/-0.010 (Pickard);
13.89900, 11.2 (G. Poyner, Birmingham, UK);
13.91940, 10.93 (Domingo Martinez);
13.95486, 11.0 (J. Ripero, Madrid, Spain);
13.96460, 11.3 (Amorim);
14.10569, 10.918 V +/-0.029 (E. Schwendeman, Fincastle, VA);
14.10832, 11.542 B +/-0.033 (Schwendeman);
14.19653, 11.1 (Maloney);
    
Charts: Charts with a comparison star sequence for ASASSN-V J195442.95+172212.6 = Vend47 may be created using either name and the AAVSO Variable Star Plotter (VSP). Brad Walter of the AAVSO Sequence Team suggests "using a 40 min FOV. All of the stars fall in a 30 min FOV centered on the target but two are very near the western edge of a 30 min field."

Submit observations: Please submit observations to the AAVSO International Database using the name ASASSN-V J195442.95+172212.6 or the name Vend47. If a GCVS name is announced in an IAU Circular or CBET, please use that name.

AAVSO Forums: ASASSN-V J195442.95+172212.6 = Vend47 is the topic of the AAVSO Time Sensitive Alerts forum thread https://www.aavso.org/tcp-j195442511722281-sagitta.

and the AAVSO Cataclysmic Variables forum thread https://www.aavso.org/new-bright-symbiotic-star. Note that the name of this thread has been corrected from "new-bight-symbiotic-star".

Notes:
a. Designated TCP J19544251+1722281 when posted to the IAU Central Bureau for Astronomical Telegrams Transient Object Confirmation Page (TOCP). Some information in this Alert Notice is taken from the TOCP page.
 
Congratulations to Robert Fidrich on this discovery!

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.
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