The triple system Zeta Aquarii

Abstract

Zeta Aquarii is a bright and nearby (28 pc) triple star with a 26-year astrometric subsystem. Almost a half of the outer 540-year visual orbit has been covered in 238 years of its observations. Both inner and outer orbits are revised here taking into account recent direct resolution of the inner pair Aa,Ab. The inner orbit has a high eccentricity of 0.87 and is inclined to the outer orbit by 140+-10 degrees, suggesting that Kozai-Lidov cycles take place. The masses of the stars Aa, B, and Ab are 1.4, 1.4, and 0.6 solar. The age of the system is about 3 Gyr, and the two main components have just left the main sequence. Hypothetically, this system could have formed by a dynamical capture of the small star Ab in the twin binary Aa,B.

arXiv commentAccepted for publication in the Astronomical Journal. 9 pages, 5 figures. Complete Table 3 is available from the author

References in corpus (10)

• Validation of the new Hipparcos reduction
• The Dartmouth Stellar Evolution Database
• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• Speckle interferometry at SOAR in 2012 and 2013
• A Comprehensive Study of the Kepler Triples via Eclipse Timing
• The PHASES Differential Astrometry Data Archive. V. Candidate Substellar Companions to Binary Systems
• High-resolution imaging at the SOAR telescope
• The unusual quadruple system HD 91962 with a "planetary" architecture
• A first-order dynamical model of hierarchical triple stars and its application
• Analysing weak orbital signals in Gaia data

Cited by in corpus (12)

• Ten years of speckle interferometry at SOAR
• The evolution of stellar triples: The most common evolutionary pathways
• Orbit alignment in triple stars
• Relative orbit orientation in several resolved multiple systems
• New binaries from the SHINE survey
• TOI-179: a young system with a transiting compact Neptune-mass planet and a low-mass companion in outer orbit
• Searching for the near infrared counterpart of Proxima c using multi-epoch high contrast SPHERE data at VLT
• Multiples among B stars in the Scorpius-Centaurus association
• Investigating three Sirius-like systems with SPHERE
• Speckle Interferometry at the U.S. Naval Observatory. XXIII
• Speckle Interferometry at the U.S. Naval Observatory. XXII
• Precision speckle interferometry with CMOS detector