Notices to investigation of symbiotic binaries V. Physical parameters derived from UBV magnitudes

TL;DR

This paper presents a straightforward photometric method to determine the physical parameters of symbiotic binaries from UBV magnitudes, successfully applied to various systems with results aligning with previous models.

Contribution

Introduces a simple photometric technique to extract individual radiation components and estimate physical parameters in symbiotic binaries.

Findings

Estimated nebular electron temperatures and emission measures.

Determined the V magnitude of the cool giant component.

Results agree with independent UV-IR SED modeling.

Abstract

In the optical, the spectrum of symbiotic binaries consists of contributions from the cool giant, symbiotic nebula and the hot star. Strong emission lines are superposed on the continuum. In this paper we introduce a simple method to extract individual components of radiation from photometric UBV magnitudes. We applied the method to classical symbiotic stars AX Per, AG Dra, AG Peg and Z And, the symbiotic novae RR Tel and V1016 Cyg and the classical nova V1974 Cyg during its nebular phase. We estimated the electron temperature and emission measure of the nebula in these systems and the V magnitude of the giant in the symbiotic objects. Our results are in a good agreement with those obtained independently by a precious modelling the UV-IR SED.