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The symbiotic star StHa 169 is in outburst

ATel #9036; U. Munari (INAF PAdova), M. Graziani (ANS Collaboration)
on 10 May 2016; 17:08 UT
Credential Certification: U. Munari (ulisse.munari@oapd.inaf.it)

Subjects: Optical, Ultra-Violet, X-ray, Cataclysmic Variable, Nova, Variables

The symbiotic star StHa 169 is in outburst, possibly the first ever noted for this object. On Apr 25.9 UT we have measured U=13.133, B=13.617, V=12.823, Rc=11.963, Ic=11.108. Mean quiescence values from the UBVRI photometric catalog of symbiotic stars by Henden and Munari (2008, BaltA 17, 293) are U=16.27 B=15.32 V=13.68, Rc=12.64, Ic=11.54, thus the event is currently showing an amplitude of 3.1 mag in U, 1.7 mag in B, and 0.9 mag in V band. Similar quiescence values characterized our 2009-2015 photometric data, the Kepler satellite observations (Ramsay et al. 2014, MNRAS 442, 489) and the ASAS monitoring of this object (Pigulski et al. 2009, AcA 59, 33).

A spectrum of StHa 169 in outburst has been obtained with the Asiago 1.22m telescope + B&C spectrograph on May 6.93 UT, covering from 3300 to 8000 Ang at 2.31 Ang/pix dispersion. Compared with similar spectra recorded during the 2010-2015 quiescence period, a strong blue continuum now completely overwhelms the M giant absorption spectrum short of 6000 Ang, and the Balmer continuum is now in a much stronger emission. The [NeV] 3426 and the OVI Raman scattering at 6825 Ang, that were weakly present in quiescence, are gone. The emission lines have largely increased their integrated flux. Hbeta flux is 9.3x10(-13) erg/cm2sec, or 6.9 times the average value in quiescence, and HeII 4686 flux is 3.0x10(-13) erg/cm2sec, or 4.4 times the quiescence. The Hbeta/HeII ratio has increased from the average 2.0 of the quiescence to present 3.1 value. The width of emission lines remains sharp with no sign of a P-Cyg profile, and their radial velocity stays close to the mean -92 km/s characterizing quiescence.