The hot and the cool otbursts in the symbiotic system AG Draconis

TL;DR

This paper analyzes six recent outbursts of AG Draconis using low-resolution spectroscopy and introduces a new method to determine the hot source's temperature from optical emission lines, revealing their evolution on the H-R diagram.

Contribution

It presents a novel method for estimating the Zanstra temperature from optical lines and applies it to study outburst evolution in AG Draconis.

Findings

Determined the temperature evolution during outbursts.

Mapped outburst evolution on the H-R diagram.

Introduced a new temperature estimation technique.

Abstract

In this papper we present the analyses of the six (1998, 1997, 2001, 2002, 2003 and 2005) last outbursts of AG Draconis on the basis of low resolution visual spectroscopy. A new method to determine the Zanstra's temperature of the hot ionizing source from the optical Hb and HeII emission lines has been used. As a results we obtained the evolution of the individual outburst on the H-R diagram.