Symbiotic stars are long orbital period interacting binaries consisting
of a late-type (G-M) giant which sheds material via stellar wind or
Roche lobe overflow onto a more compact and hotter companion. The hot
star provides an intense ultraviolet radiation field which ionizes a
portion of the surrounding nebula, giving rise to emission lines like
HI, HeI, HeII and [OIII] seen in these variables, while characteristics
like strong red continuum, TiO and VO absorption bands, absorption
lines of neutral and singly ionized metals are associated with the
late-type star. The compact object in symbiotic stars is in most cases
a white dwarf, which can derive its high luminosity and temperature by
releases of potential energy in an accretion disk or as result of
burning of hydrogen being accreted by the white dwarf or even from the
cooling of an object resembling a nucleus of a planetary nebula. Low
mass main sequence stars with an accretion disk can also occur as the
ionizing source in such systems. For more details about the symbiotic
stars see, e.g., Friedjung & Viotti (1982);
Kenyon (1986) and Miko
ajewska et al. (1988).
Table 1: Log of the spectroscopic observations
In a previous paper (Cieslinski et al. 1994) we presented observations
of 6 symbiotic star candidates. In this paper we describe observations
of two additional variables that we suggest as newly identified
symbiotic stars. They show emission lines of HI, [OIII] and HeII
4686, characteristics of this class of variables.
Figure 1: Spectra of DQ Ser (a, b, c, d) and DT Ser (e, f). The
fluxes are in units of
10
erg cm
s
Å
photometry