Orbits and Structure of the Quadruple Systems GJ 225.1 and FIN 332

• Published in: Astronomy letters Vol. 46; no. 9; pp. 612 - 620
• Main Author: Tokovinin, A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.09.2020; Springer Nature B.V
• Subjects: A stars; Astronomy; Astrophysics and Astroparticles; Inclination; Observations and Techniques; Orbital elements; Orbits; Physics; Physics and Astronomy; stars binary; stars multiple
• ISSN: 1063-7737; 1562-6873
• DOI: 10.1134/S1063773720090078

Only a handful of quadruple systems with two accurate inner visual orbits are known. The architecture of two such systems is studied here to determine the period ratios, mutual orbit orientation, and other parameters; updated orbital elements and their errors are derived. Gliese 225.1 (HIP 28442) is composed of three K-type and one M-type dwarfs and has inner orbital periods of 67.2 0.2 and 23.4 0.5 yr. Its inner orbits have a small mutual inclination and are likely coplanar with the outer orbit of kyr period. The quadruple system FIN 332 (HIP 92037) consists of four early A type stars with similar masses and magnitudes. Both its inner orbits with periods of 27.6 0.2 and 39.8 0.4 yr have large eccentricities (0.82 and 0.84). Their orientation in the sky is remarkably similar. In contrast, the outer orbit with a period of kyr has a large relative inclination to the inner orbits. The dynamics and formation of these quadruple systems are briefly discussed.