Title:
Nature of Z And-type outbursts in symbiotic binaries

Author:
A. Skopal

Abstract:
At present, nature of the so-called Z And-type outbursts in
symbiotic binaries is not well understood. Using own methods
in analysing recent explosions of symbiotic stars AG Peg (2015)
and HBHA 1704-05 (2018) I found that the outbursts are caused
by an abrupt increase of the mass-accretion rate onto the white
dwarf (WD) that results in a dramatic increase of the nebular
emission, the WD's temperature of ~200,000 K and its luminosity
of ~20,000 solar units. The nuclear-burning WD blows a strong
stellar wind and generates the luminosity around the Eddington
limit, at which the light energy balances the gravitational force
of the WD. Revealing the nature of Z And-type outbursts point their
connection to the so-called symbiotic nova outbursts and allows us
to understand relationships between basic types of symbiotic stars.