The spectroscopic orbit and the geometry of R Aqr

Abstract

R Aqr is one of the closest symbiotic binaries and the only D-type system with radial velocity data suitable for orbital parameters estimation. The aims of our study are to derive a reliable spectroscopic orbit of the Mira component, and to establish connections between the orbital motion and other phenomena shown by R Aqr. We reanalize velocity data recently published by McIntosh & Rustan complemented by additional velocities. We find an eccentric orbit (e=0.25) with a period 43.6 yr. This solution is in agreement with a resolved VLA observation of this system. We demonstrate that the last 1974-1981 increase of extinction towards the Mira occured during its superior spectroscopic conjunction, and can be due to obscuration by a neutral material in the accreting stream. We also show that jet ejection is not connected with the orbital position.

7 pages, 4 figures, accepted for publication in A&A

References in corpus (2)

• Outer jet X-ray and radio emission in R Aquarii: 1999.8 to 2004.0
• A Review of The O--C Method and Period Change

Cited by in corpus (5)

• Numerical Simulations of Wind Accretion in Symbiotic Binaries
• Large-scale environments of binary AGB stars probed by Herschel - I. Morphology statistics and case studies of R Aquarii and W Aquilae
• First detection and characterization of symbiotic stars in M31
• Characterization of the Most Luminous Star in M33: A Super Symbiotic Binary
• A Comparison of the Velocity Parameters of SiO v=1, J=1-0 and J=2-1 Maser Emission in Long Period Variables