Affiliation:
1. Astronomical Institute, Faculty of Mathematics and Physics Charles University Prague Czech Republic
2. Astronomical Ring for Amateur Spectroscopy Group Sydney Australia
3. 2SPOT Southern Spectroscopic Project Observatory Team Châbons France
4. Astronomical Observatory University of Warsaw Warszawa Poland
Abstract
AbstractThe poorly studied variable star V390 Sco, previously classified as a Mira pulsator, was detected in a brightening event by the ESA Gaia satellite in September 2023. This work presents an analysis of available archival multifrequency photometric data of this target, along with our spectroscopic observations. Our findings lead to the conclusion that V390 Sco is a new symbiotic star identified by Gaia, currently undergoing a classical symbiotic outburst. Additionally, we uncovered three prior outbursts of this system through archival photometry. The outbursts recur approximately every 2330–2400 days, and we hypothesize the periastron passage in an eccentric orbit may trigger them, similarly to the case of BX Mon, DD Mic, or MWC 560. A detailed investigation into the nature of the donor star suggested that V390 Sco is an S‐type symbiotic star, likely hosting a less evolved, semiregularly pulsating giant donor, but not a Mira variable.
Funder
Univerzita Karlova v Praze
National Aeronautics and Space Administration