The symbiotic binary St 2-22: Orbital and stellar parameters and jet evolution following its 2019 outburst

Abstract

St 2-22 is a relatively poorly studied S-type symbiotic system that belongs to a small group of jet-producing systems as a result of disc accretion onto a white dwarf fed by its red giant companion. The goal of this paper is to analyse the nature and derive the basic parameters of St 2-22, and to follow the jet evolution. Photometric monitoring for over 16 yrs and high-quality spectroscopic data enabled us to shed new light on its nature. The high-resolution SALT spectra and $V{I}_C$ photometry obtained during and between the last two outbursts have been used to search for periodic changes, to derive spectroscopic orbits of both system components, and to study the outburst and jet evolution. We present the orbital and stellar parameters of the system components. The orbital period is $P_{orb}=918\pm 6^d$. The double-line spectroscopic orbits indicate the mass ratio $q=M_g{M}_h^{-1}=3.50\pm 0.53$, and the components masses $M_g{\sin }^{3}i\sim 2.35$ M${}_{sun}$ and $M_h{\sin }^{3}i\sim 0.67$ M${}_{sun}$. The orbit shows significant eccentricity, $e=0.16\pm 0.07$. The orbital inclination is close to 70 degrees. During outbursts, accelerating and decelerating jets are observed with changes in their radial velocity component in a range from $\sim 1500$ up to nearly $1800$ km s${}^{-1}$. St 2-22 turned out to be a classical symbiotic system very similar to the precursor of the group - Z And.

arXiv commentAccepted for publication in Astronomy & Astrophysics

References in corpus (15)

• The chemical composition of the Sun
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• Comprehensive analytic formulae for stellar evolution as a function of mass and metallicity
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• TAPAS, a web-based service of atmospheric transmission computation for astronomy
• Signatures of SN Ia in the galactic thick disk
• Spectroscopic orbits and variations of RS Oph
• Transient jets in the symbiotic prototype Z Andromedae
• The spectroscopic orbits and the geometrical configuration of the symbiotic binary AR Pavonis
• Rotational velocities of the giants in symbiotic stars: III. Evidence of fast rotation in S-type symbiotics
• The symbiotic recurrent nova V3890 Sgr: binary parameters and pre-outburst activity
• Gaia18aen: First symbiotic star discovered by Gaia
• High resolution spectroscopy of symbiotic stars. VI. Orbital and stellar parameters for AR Pav

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