The Curious Case of ASAS J174600-2321.3: an Eclipsing Symbiotic Nova in Outburst?

TL;DR

This paper analyzes the peculiar variability of ASAS J174600-2321.3, identifying it as a likely eclipsing symbiotic nova in outburst, with detailed data analysis revealing its binary nature and outburst characteristics.

Contribution

It provides the first comprehensive data analysis identifying ASAS J174600-2321.3 as a long-period eclipsing symbiotic binary in outburst, suggesting its classification as a symbiotic nova.

Findings

ASAS J174600-2321.3 is a long-period eclipsing binary with Porb = 1011.5 days.

The primary is likely a white dwarf in outburst with an early F-type spectrum.

The secondary is a late M-type giant.

Abstract

The star ASAS J174600-2321.3 was found to exhibit peculiar photometric variability (conspicuous brightening of about 4 magnitudes (V), fast luminosity declines, intrinsic pulsations). It was rejected as an RCB candidate in recent investigations on spectroscopic grounds. We have collected and present all available data from public sky surveys, photometric catalogues, and the literature. From an analysis of these data, we have identified ASAS J174600-2321.3 as a long-period eclipsing binary (Porb = 1011.5 days). The primary star, which is probably a white dwarf, is currently in outburst and exhibits the spectral characteristics of a reddened, early F-type supergiant; the secondary star is a giant of spectral type late M. We discuss the possible origin of the observed brightening, which is related to the primary component. ASAS J174600-2321.3 is most certainly an eclipsing symbiotic binary - probably a symbiotic nova of GCVS type NC - that is currently in outburst. However, further photometric and spectroscopic data are needed to confirm this.