Friday, August 7, 2020

Four stars

There are a couple of solar systems out there which we have observed with four stars, something right out the movies.

Orbits and structure of quadruple systems GJ 225.1 and FIN 332

Only a handful of quadruple systems with two accurate inner visual orbits are known. Architecture of two such systems is studied here to determine 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 small mutual inclination and are likely coplanar with the outer orbit of ~2 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 ~5 kyr has a large relative inclination to the inner orbits. Dynamics and formation of these quadruple systems are briefly discussed.
Comments:Accepted for publication in Astronomy Letters. 6 pages, 5 figures, 3 tables
Subjects:Solar and Stellar Astrophysics (astro-ph.SR)
Cite as:arXiv:2008.02361 [astro-ph.SR]
 (or arXiv:2008.02361v1 [astro-ph.SR] for this version)

1 comment:

Ryan said...

Too bad we aren't in one of those systems. Much greater incentive for space exploration.