Identification of new Galactic symbiotic stars with SALT -- II. New discoveries and characterization of the sample

TL;DR

This study reports the discovery and detailed characterization of 14 new Galactic symbiotic stars, using SALT spectroscopy and photometric analysis, thereby expanding the known population of these complex binary systems.

Contribution

It presents the identification of new symbiotic stars and provides their spectral and photometric properties, including variability and potential orbital periods, based on systematic survey and follow-up observations.

Findings

14 new symbiotic stars confirmed

6 strong candidates identified

Evidence of variability and outbursts in several systems

Abstract

We present the continuation of a systematic search for new southern Galactic symbiotic stars, selecting candidates from the SuperCOSMOS H$\alpha$ Survey and 2MASS. Follow-up spectroscopy with the Southern African Large Telescope (SALT) was used to confirm their symbiotic nature and to characterize the cool and hot components of the full sample, including systems from earlier work. We report 14 newly confirmed bona fide symbiotic stars and identify 6 additional strong candidates. Photometric variability was examined using our data and archival light curves from multiple all-sky surveys. Most systems are variable, with the majority showing periodic modulation consistent with orbital motion or pulsations. Possible photometric orbital periods are reported for 19 confirmed and 3 candidate systems, pending spectroscopic confirmation. Eight objects exhibit signs of outburst activity. In one of the systems, multiple brightenings occur at similar orbital phases, closely resembling the evolution of FN Sgr, a symbiotic binary with a magnetic white dwarf. The peculiar variability of another symbiotic star is best explained by dust-obscuration events. These results expand the census of Galactic symbiotic stars.