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.
